Passion for Panerai

Buying items on Ebay can be scary. You never know whether you’re going to get what you paid for or just a box filled with stones. In some rare cases though, Ebay has proven to be a wonderful platform for finding true gems. The following story is such a case.


Radiomir Panerai Type D Rolex Movement 618 as is for parts

A while ago, in January 2016, I received an Ebay alert for a Rolex Cal. 618. Most Rolex Cal. 618 offered on Ebay are actually Cal. 622 from thin Rolex pocket watches, so I didn’t check the listing immediately. However, later that day, people started sending me emails and asking whether I saw the amazing listing on Ebay and if the parts were original or not. Of course, I quickly went to see what all the fuss was about.

The item was listed as “Radiomir Panerai Type D Rolex Movement 618 as is for parts”. The main image showed indeed what looked like an overgrown early Rolex Cal. 618 made by Cortebert. The condition was awful. What happened to this movement?

At second glance I spotted what appeared to be a Ref. 3646 movement ring, as used from 1940 until 1943. Wait a minute, I said to myself, what is this…?

“Overgrown” Rolex 618 Type 1a, made by Cortebert


I browsed swiftly through the images. The next photo showed a heavily damaged rivet dial. I started to get excited. Most of these early Panerai dials shrunk over time and so did this. There was also an hour hand and a broken minute hand… and a bezel.

Heavily damaged rivet dial


The photos were not very sharp, which in many cases is a very bad sign. Someone could deliberatly try to hide important details in order to fool people. Not in this case.

The inside of the case back was adorned with a typical Perlage finish, the stamps said Oyster Watch Co.

Ref. 3646 was produced between 1940 and 1944. Rolex, the producer of these watches, adjusted the style of the case back stamps several times during this period. Seven different groups could be identified in the past (Type A, B, C, D, E, F and G).

The stamps on this case back, in combination with the case number 1010039, belong to the Type B group from around 1941.

3646 Type B case back


It is worth mentioning that 7-digit case numbers actually form part of the Rolex pocket watch line. It is unknown why Rolex chose to produce the first three 3646 groups (Type A, B and C) within the pocket watch line. Ref. 3646 is basically an Oyster pocket watch from 1926 that was turned 90 degrees. Wire lugs were then soldered to the case to create a wrist watch.

Evolution of the Rolex Oyster pocket watch into Rolex Ref. 2533


At some point though, Rolex must have reconsidered these watches and produced the final batches from 1944 (Type D, E, F and G) within the regular Oyster line.

Coming back to the Ebay listing, the case back bore a strange matricultaion number on the outside. A simple No. 07. Never seen anything similar before, but more on this later.

Simple matriculation number on the outside of the case back


An onion-shaped Brevet crown with stem was also part of the deal. Connoisseurs of the brand know what to look for and this was without a shadow of a doubt a genuine part.

Onion-shaped Brevet crown (Rolex No. 11)


One picture later, another spectacular piece appeared, a Ref. 3646 middle case with missing wire lugs at 12.


3646 middle case


The lugs at 6. This picture makes clear that the wire connection on right had already been re-soldered.



The missing lugs at 6. This is a common damage for early Ref. 3646 watches. The wire lugs were a known weakness of the case construction and frankly, together with the whole 3646 case construction, a relic of the late 1920s.

While the first Ref. 3646 watches were delivered to Panerai in April 1940, Rolex was already producing a new generation of Oyster cases with lugs carved out of the same block of steel for many years. Ref. 3646 it seems, was a budget solution based on old technology.

Missing wire lugs at 6


A closer look at the middle case and the crown tube.

Inside of the 3646 middle case with the crown tube


At this point it started to dawn on me, this pile of junk was an almost complete vintage Panerai 3646 and totally new to the market. A fantastic restoration project for someone with skills and passion.

The seller described the watch well and tried also to explain its bad condition:

There is an extensive amount of oxidation as seen in pictures due to being in a fire.


Whether the story with the fire was true or not is irrelevant in my opinion. What matters more is that all parts appeared to be absolutely genuine. I learned that several highend vintage dealers were watching this listing as well but I guess most were unsure whether they would end up with a gem or dumping their money for ever.

Anyway, the watch was sold a few days later for the incredibly low amount of US $ 17,300.00. I registered the watch in my database and forgot about it… until recently.

Ebay listing: Radiomir Panerai Type D Rolex Movement 618 as is for parts


Restoration in process

In March 2017, I was contacted by the new owner of this watch. The watch had been taken completely apart and the new owner wanted to see whether the movement serial number fitted into the picture. It did.

I received several photos showing the restoration process. All parts as they arrived.

The received parts


The new owner took the movement apart, cleaned eveything and got it running again. Minor things like the pallet fork and the click spring had to be replaced. He also soldered a new wire lug onto the case.

Serviced movement and re-soldered wire lug


Initially , I thought the matriculation number “No. 07” is unique. But I was able to find a 3646 with a very similar number. The number on this particular watch is “No. 010”.

3646 with matriculation number “No. 010”


The front of “No. 010” reveals that the watch was updated, possibly during the 1950s. The dial and the hands are typical items from the 1950s.

3646 “No. 010” with 1950s dial and hands


It is difficult to say whether these watches belonged to a certain unit of the Decima MAS or if it was applied later. During my last trip to Italy in May 2017, I went to see Mr. Ferretti and asked him if he knew anything about this type of numbers but he had not seen anything similar before.

So far, only two types of Italian 3646 matriculation numbers are known, “Xa FLOTMAS No. XXX” and “12-42-XX”.

Below you can see the two types of engravings. Xa FLOTMAS 048 appears to refer to SLC crews (manned torpedoes) whereas 12-42-37 (obviously not a date) may have belonged to Gruppo Gamma members (combat swimmers).


Decima MAS matriculation numbers


However, it is known that MTM pilots (explosive boats) used to wear Panerai watches as well.

The following gentleman is Giorgio Giobbe. He was the head of the Decima MAS surface units (MTM, MTS). Giorgio was killed by British RAF aircraft fire, during the retreat from a failed attack on the British Naval Base in Malta on July 26, 1941. A total of 16 Italians were killed during that mission, among them also Teseo Tesei, the father of the SLC (manned torpedo). 18 men were taken prisoneer, and only 11 managed to escape.

You can clearly see on this photo that Giorgio Giobbe was wearing a Panerai watch.

Giorgio Giobbe, commander of the Decima MAS surface units wearing a Panerai watch


Let’s go back to the watch in question. The shape of the cushion is absolutely matching with the first series of Ref. 3646.

Case profile


Early middle cases (Type A, B and C) were asymmetric. The upper arch (a) of the cushion is higher than the one at the bottom (b). From Type D on, the cases became completely symmetric.

Asymmetric profile visualised


The dial is probably the biggest issue. It will be difficult to source an early rivet dial in a good condition.

These were probaly the earliest Panerai dials, not the California dials as claimed by Officine Panerai. California dials came only in 1944, after Panerai was no longer able to produce sandwich dials.

The initial rivet dials were prone to deformation due to heat. A severe warping would block the hands, and thus compromise the entire watch. Panerai solved this problem with the development of alluminium sandwich dials.

Damaged rivet dial


The new owner took the dial apart. Here you can see the three different layers.

Layers of a rivet dial


The indices and markers on the first layer are still visible under the light. The font used for the Radiomir Panerai inscription makes clear that this is a second generation rivet dial.

Layer with indices and markers


It seems that Panerai outsourced the production of these early dials, or at least their backplate. The manufacturer was Zelime Jacot (now Cadrans Flückiger SA) , a Swiss dial manufacturer from St. Imier. The backplate bears the numbers 56 (Client) 9185 (Reference) and ZJ.

Backplate with Zelime Jacot stamps


More about Panerai dials: Vintage Panerai – A dial taxonomy

Many “Italian” Ref. 3646 watches remained in service during the 1950s. In order to do so, their dials and hands had to be replaced.

Radium lume was a mixture of radium and zinc sulfide. The high radiation of radium hit the zinc sulfide, which in response started to emit light. After 3 to 5 years, the zinc sulfide desintegrated and the glow effect was gone. Panerai was probably asked to replace those dials and hands. This was a common procedure.

The following watch is a good example. It belonged to Luigi Durand de la Penne. Luigi played a crucial role as a SLC pilot in the most successful attack of the Decima MAS in December 1941. He lost his watch during the attack and after the war, he received the one you see below. This watch is updated with a 1950s dial and corresponding hands.

This watch is exhibited at the COMSUBIN Base in Le Grazie.

Luigi Durand de la Penne’s 3646


Another watch that was obviously updated with a 1950s dial is XA FLOTMAS 01 from the Museo Tecnico Navale della Spezia. This watch belonged to Ernesto Notari, another SLC pilot of the first hour.

Ernesto Notari’s 3646



A genuine 1950s Panerai dial would be a valid replacement for the damaged rivet dial in my opinion. Another possibility would be to try and recreate a rivet dial based on the genuine ZJ baseplate and according to the original construction.

I wonder why Officine Panerai has never tried to reissue this type of dial. Its construction was engineered to maximise its glow effect. They must have been amazing back in the days.



I would like to thank the owner of this fantastic watch for giving me the opportunity to fully document yet another amazing watch and share this fantastic story with Panerai enthusiasts around the world. I will try my best to help sourcing the missing parts.


Second generation rivet dials play an important role in the Panerai timeline. Please click the image to zoom in and/or download the highres file.



This timeline is available as a 150 x 85 cm (59 x 33 inch) high quality print.

Regular: EUR 120.00 (plus shipping)

Limited: 50 pieces, numbered and signed by Maria Abetti Panerai, the widow of Giuseppe Panerai at the historical site of the Villino Panerai (Panerai Villa) in Florence: Sold out

More information: The history of Panerai watches at a glance


Thank you for your interest.

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