Rolex-Panerai 3646 ‘Error Proof’ From A Bosnian Bazaar

The following story revolves around what could be one of the most incredible horological finds of the century but more than that, it is a heartwarming account of how following your instincts can put you on a trajectory for a better life for you and yours. It is also a story about passion, fairness and basic decency. The events that carried this timepiece to the most unlikely place on Earth were set it in motion some 75 years ago.

Historical Background

The final days of World War 2 in Italy were a concatenation of precipitating events. The German forces which had occupied the country since September 1943 were on the retreat. The Italian partisans and the secret services of the Allied forces, both were hunting down Italian fascists. While the partisans wanted them dead for the atrocities commited to the Italian population, the Allies needed some of them to help fight communism which was on the rise from the east. Fearing the Germans would destroy the two most important Italian ports, Commander Eugenio Wolk, leader of the ‘Gruppo Gamma’ frogman unit of the ‘Decima MAS’ sent his best men to La Spezia and Venice to protect crucial port infrastructre. The Allied campaign which had begun in July 1943 with the invasion of Sicily, ended almost abruptly in late April 1945. German combat divers (Kampfschwimmers) scattered around Venice ready to sabotage arriving Allied ships were taken by surprise and fled to Trieste to avoid capture. Trieste, however, was surrounded by Tito’s Yugoslav 4th Army and would soon be overrun. Almost 3,000 Germans were killed in this final battle, between 4,000 and 5,200 were taken prisoner. A small number of German combat divers managed to escape undetected and some reportedly gifted their Rolex diving tool watches to locals who helped them out.

The Old Bazaar In Sarajevo

Fast-forward to our time. A young Bosnian fellow who deals in watches as a side hustle was strolling through the old bazaar next to the ancient mosque in Sarajevo when suddenly a peculiar looking watch caught his attention. The dial had half-Roman, half-Arabic numerals but was completely unbranded, except for the small ‘Swiss Made’ designation at six o’clock.

Watch found at the local bazaar in Sarajevo


The movement was unbranded as well. Besides a 6-digit number there was nothing on the inside of the caseback that could identify the maker of this thing.

Watch found at the local bazaar in Sarajevo


The watch was the size of a pocket watch. The cushion case featured soldered wire lugs so that it could be worn on the wrist. A pocket watch for the wrist? Maybe one of the famous trench watches from WW1? Our young fellow had no idea what he had come across but instinctively negotiated a good price and took it home for a fistful of Euro coins. How much is a fistful you ask? 15, one five, but pssst, do not tell anyone or the bazaar will soon be overrun by drooling watch dealers in hippie clothes!

The Facebook Listing

In mid December 2020, our young fellow decided to part with the weird thing and listed it in a closed Facebook watch group from the Balkans. The price? EUR 350. Not bad of a markup! This is where I got involved. The next day, I woke up to a dozen or so Instagram direct messages all revolving around the very same question. Is it real? The pictures were of low quality but knowing what to look for there could only be one answer. Yes, that thing next to the lighter, which was placed next to the watch for size reference, was the real deal! It was morning in Malaysia so the guys who texted me were sleeping by then. I went about my day and almost forgot about the watch until about 3 p.m. when more messages started coming in. Of course, Europe had just woken up. I told the guys the watch was real. Except for the odd hands and the crown, everything was spot on. Someone offered 1,000 Euros, another 3,000 but our young fellow had already sold the watch the night before for EUR 350 and… despite the cosiderably higher new offers, he wanted to honour his word! Say again? Honour his word? What a rare breed this young fellow!

This is where my Slovenian buddy Jay aka @vintage_kronos came into the picture. Made aware of the situation by a friend of his, Jay was willing to pay a fair price for the watch if it was real. He shot me a message and without even awaiting my ok on the authenticity, Jay moved heaven and earth to get in touch with the young fellow. He managed to find and call the lad and just as he articulated his offer, the young fellow’s doorbell rang. Remember the buyer from the night before? He had travelled all the way from Croatia to Bosnia to get his hands on the watch as quickly as humanly possible. The guy insisted in getting it for the agreed 350 Euros. In my opinion, this individual knew exactly what it was (or could be) and was trying to pull a fast one. Long story short, the young fellow finally came to his senses and accepted Jay’s generous offer instead.

A Grail Hunt

What followed was a veritable grail hunt in Indiana Jones fashion. In midst of the Covid-19 pandemic, Jay decided to take his chances and drive to Bosnia, accompanied by a friend. Crossing the Slovenian-Croatian border went smoothly. At the Croatian-Bosnian border, however, things started getting complicated. While the Croatians let them through, the Bosnians a few meters further ahead denied them entry. No negative Covid test, no passing! A phone call later, the young Bosnian fellow and his father were racing in a yellow car towards the Croatian border to try to get the deal done. Since the father had Bosnian-Croatian dual citizenship, the Croatians would not turn him down, they believed. Once at the border, they were waved through by the Bosnians but stopped and sent back by the Croatians. From his position, Jay could see the yellow car reversing and turning back to the Bosnian checkpoint. In a fraction of a second, all hope was lost. But wait, what about that ‘no man’s land’ strip between the checkpoints? Jay had a flash of genius! He quickly called the two and asked them to stop the car immediately. Jay and his friend then passed the Croatian check point again, this time accompanied by good luck wishes from Croatian officers who had witnessed their first futile attempt at crossing the border. Jay’s grail watch was now within reach. Just a few more meters. They parked next to the yellow car and the young fellow beamed into their vehicle to seal the deal. The watch changed hands, so did a thick roll of cash.

Minutes later, Jay sent me the following picture:

“In my hands now. Did it!”


The next day, Jay and I talked on the phone. Jay’s excitement over his grail was absolutely contagious and I listened with great interest to how rewarding his journey had been. The next step was to examine the watch in detail, meaning the watch had to be taken apart. Jay was nervous but I gave him a crash course in disassembling the 3-piece Oyster case and afterwards he felt confident he could pull it off. A few days later, he sent me some very detailed pictures which only confirmed what I knew all along.

Rolex 3646 ‘Error-Proof’ dial, 261002

Jay’s photos give us a great insight into the details and condition of the watch. The ‘Error-Proof’ dial which people today often refer to as ‘California’ dial appears to have been exposed to moisture over a long period of time. This led to a distinct darkening of most radium numerals.

Rolex-Panerai Ref. 3646, Error-Proof dial, 261002


A plausible explanation for the dial condition could be the lack of a screw-down crown. The current crown is probably from a pocket watch. To accomodate it, the threads of the original crown tube were filed down. This construction left the inside of the watch open to moisture ingress. The hands are obviously not original. These are so-called ‘Louis XV’ pocket watch hands which collide visually with the ‘Art Deco’ style of the dial. Given the condition of the dial, it can be assumed the original heat blued steel hands became rusty and were replaced for cosmetical reasons.

The ‘Error-Proof’ dial with half-Roman, half-Arabic numerals is a patented Rolex design filed on May 30, 1941 (CH221643). The goal, as described in the patent, was to create an easy-to-read dial with large numerals which could be painted with as much radium lume as possible. Claims it was created as a sample dial or that it was made to confuse the enemy are false. Today this type of dial is known as ‘California dial’ which is supremely ironic given the term was originally used to refer to fake dials refinished in Error-Proof fashion by a dial refurbisher from California. To read more about this click the link below.

Read more A Californian controversy: The origins of the term ‘California dial” (Fratello)

Rolex ‘Error’Proof’ advertisement from the early 1940s


To disassemble Ref. 3646, the caseback needs to be removed first. This was almost certain a German Kampfschwimmer watch but it does not bear any corresponding markings.


Once the caseback is unscrewed, the markings on the inside can be inspected. Since this is a completely anonymous Rolex 3646, the only markings are the case number stamps 261002.


While 261002 is a Rolex case number from 1943, the watch was delivered to Florence in mid 1944. Rolex produced a total of 720 pieces in this particular case number range which extends from 260405 to 261125 but the watches were produced and delivered in batches. The first batch (260405 – 260695) was delivered in mid 1943. These watches had a thicker case (6.3 mm) and a tall bezel to accomodate the thick sandwich dials (~2.5 mm) provided by G. Panerai & Figlio. Further batches were sent in 1944 (260696 – 260849, 260850 – 261125). These had slimmer cases (5.4 mm vs. 6.3 mm) and low bezels. All of them were equipped with thin Error-Proof dials. Due to the low bezels, these watches do not have enough clearance to take thick Panerai sandwich dials.

Watches from the case number range 260405 – 260849 have Rolex markings on movements and casebacks but the case number range 260850 – 261125 is completely anonymous. The movements of the latter are unbranded and the casebacks were machined to remove existing Rolex stamps. The case numbers were also removed in the process but subsequently restamped at a different position closer to the edge. The picture below shows an example (260889) where the Rolex stamps are still slightly visbible.

Removed Rolex stamps (right-hand side: Rolex stamp superimposed)


This was done by Rolex to conceal the origins of the watches after learning they were destined to Nazi forces stationed in Italy. Rolex’s agreement with Panerai was exclusive to the Italian Navy but with Florence occupied by Nazi forces, Rolex could not stop delivery for fear of severe retaliation against their retailer Panerai. By anonymizing the watches, Rolex killed two birds with one stone. Saving the Panerai family from getting into trouble while at the same time protecting Rolex’s reputation.

Read more: Fake Rolex stamps on anonymous Rolex-Panerai Ref. 3646 watches


The movement of this watch is a refined 17 jewels version of the Cortébert 618 specifically produced for Rolex. This particular variation is, except for Fab. Suisse, completely anonymous.


The patina which developed on the bridges is quite consistent with the condition of the dial and probably a result of moisture ingress over a long period of time. The comparison below shows the difference between a branded Rolex 618 caliber and the anonymous version.

Branded vs. anonymous


To further disassemble the watch, the crown needs to be removed. This is done by slightly loosing the setting lever screw (vis de tirette) next to the crown wheel. Once the crown with the crown stem is out, the ensamble consisting of movement, movement retaining ring and bezel/crystal can be taken out of the middle case. Now, the bezel with the crystal can be unscrewed from the movement retaining ring in order to get access to the dial and hands.


Ref. 3646 (1940 – 1944) was a minor evolution of Ref. 2533 (1936 – 1939) which was based on the earliest Oyster case from 1926 seen below.

Rolex Oyster from 1926


Jay disassemled the watch further by taking the movement out of the movement retaining ring and removing the dial. Once done, the movement serial number which is located on the dial side of the main plate becomes visible. The number found on the plate is absolutely consistent with other pieces from the same batch.

Movement serial number


Another important detail are the dial maker markings on the back of the ‘Error-Proof’ dial. These dials were made by dial maker Stern Frères in Geneva. The back of the dial is marked with a star which was Stern’s logo. Stern is a German name and means star. The number 103 was Stern’s client number for Rolex and 2802 was the reference number of the dial itself.

Stern Frères markings


Putting the watch back together is a bit more complicated but Jay did a tremendous job. Due to lack of original parts, Jay bought an after market crown and hands to return the watch visually to its original condition until proper parts become available. If you have these parts, please contact @vintage_kronos.

Jay’s grail, visually restored to original condition


I advised Jay to get in touch with Kostas Venizelos of Kostas Straps to get some proper leather for his grail. Kostas studied historical Rolex-Panerai straps to exhaustion and knows everything about them. In addition, his craftmanship is second to none.

One more thing, the young Bosnian fellow told Jay he would use a large chunk of the money to send his younger sister to university. What a rare breed indeed!

The Panerai Time Machine

The final batches of Ref. 3646 were witnesses to important historical events and are crucial pieces of the Panerai puzzle. The timeline below represents the current state of research into vintage Rolex-Panerai watches. Click to zoom in.


This timeline is available as a high quality print in two sizes:

  • 120 x 68 cm (47 x 26 inch): EUR 85.00 (plus shipping)
  • 150 x 85 cm (59 x 33 inch): EUR 120.00 (plus shipping)

Printed with HD Inkjet on photo paper and laminated.

Limited edition: 50 pieces, numbered and signed by Maria Teresa Panerai in Giuseppe Panerai’s very own laboratory at the historical site of the Villino Panerai (Panerai Villa) in Florence: Sold out

To order shoot me a DM on Instagram: @perezcope

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