Doxa Information on age and works

Since there is little information on Doxa watches before the Sub-SUB era and few clues for identification, I would like to share with you all the information I could gather.

SERIAL NUMBER SYSTEM 1940–1966

In 1940, Doxa introduced a seven-digit serial numbering system, with the first two digits corresponding to the year of manufacture. In other words, 40XXXXX corresponds to 1940, and so on. The serial number is always stamped on the outside of the caseback.
The movements bore a Doxa stamp but no serial number.
BEFORE 1940: The archives were destroyed by a flood in 1966. If the doxa you are trying to identify does not follow this pattern, there may be three reasons:

1. In the 1950s there was apparently an additional numbering system
2. Before 1940: If the serial number does not follow the 7-digit pattern and the watch is equipped with an Aurore-Villeret 110 movement (wristwatches) or an FHF with modified bridges (pocket watches), the decade of manufacture is sufficient.

If you own a Doxa watch with a date, that's great. Otherwise, dating it to the nearest decade is as good as you can get. For a wristwatch with an AV 110 movement, it's most likely from the 1930s.

3. Frankenuhr: If the case doesn't have a correct Doxa stamp on the inside, don't buy it. Even if there's a 7-digit serial number on the back, if the first two digits don't make sense (e.g., 41 on a watch with an ETA 1080 and a 1950s look), you can be pretty sure it's a standard case. Finding a standard case isn't a problem with completely ordinary movements.

HOUSING

Doxa uses chrome-plated, gold-plated, and solid gold cases. Some of these were made by external manufacturers such as Maeder-Leschot or Paul Bovier. In such cases, the case back still bears the Doxa serial number and Doxa stamp.
CAUTION WITH SOLID GOLD CHRONOGRAPHS! Doxa uses Landeron and Valjoux movements.

The use of Landeron raises the possibility (sadly confirmed) that Chronographe Suisse "converted" Doxa watches with wafer-thin gold cases. However, if there's an unsigned Landeron inside, or one with a shabby "Doxa" marking, the case is wafer-thin (optional: with hollow lugs), and everything about it screams "Chronographe Suisse," then it's probably a Chronographe Suisse.

Cases not properly labeled, whether gold, gold-plated, or chrome-plated? Stay away!

CLOCK MOVEMENTS.

In the 1930s and well into the 1940s, Doxa used a "workhorse" movement—the Aurore-Villeret 110. Many sellers try to advertise with phrases like "in-house Doxa movement" or "manufactured Doxa movement." Keep in mind that such a thing doesn't exist, except for one or two ladies' movements from the 1960s. That's it. The Felsa 55 was also used (according to the entry for this movement in the Ranfft archives).

In the early 1940s, Doxa began using ETA movements – usually with a number of bridge modifications, making it difficult to find the correct movement in the Ranfft archives. As always, the decisive factors for identifying the ebauch manufacturer and caliber are the shape of the balance cock and (if you're lucky and have a good picture of the movement) the tiny markings under the balance.

In the early 1950s, Doxa used a new generation of ETA movements—the 1080, 1100, and their derivatives. Models from around 1950 were not equipped with shock protection.

In the mid-1950s, Doxa also used Chezard's stationary seconds movements – whose bridge shapes remained virtually unchanged by Doxa standards.
The automatic movements used by Doxa were mostly ETA movements. I'd bet the usual few percentage points that I'm mistaken and that they actually used non-ETA automatic movements.

I've heard of examples with bumper movements - but I've never seen a Doxa with one, so I can't prove that they existed.
There are Doxa watches with triple date and triple date and moon phase – except for one module, the manual winding is basically identical, only the bridges have been modified by Doxa.

Dials:

Wristwatches from the late 1920s to the late 1950s can feature three types of the Doxa logo:

Painted capital letters, with the D significantly larger than the rest of the font. 2. Painted capital letters, with the D almost identical in size (although barely noticeably larger) to the rest of the font. CAUTION!

I have seen examples without obvious signs of redialing, but I would not vouch for a watch with such a logo.

If you have trouble distinguishing a redial from a genuine one, you should avoid these watches...

Raised capital letters, D significantly larger than the rest of the font.
Do you see a Doxa logo like the SUB's on a 1950s model? Redial

ANTIMAGNETIQUE/ANTIMAGNETIC MODELS:

Be careful with the "Anti-Magnetique" label. It should ALWAYS be written separately.

Here are some Doxa chronographs with launch date:

1939 Chronograph Venus cal 140, hand-wound, hard gold-plated

1939 Chronograph Cal. 15, hand-wound, stainless steel, 17 jewels

1941 Chronograph Valjoux Kal 84, hand-wound, 14K gold

1944 Chronograph Landeron Cal. 48, chrome-plated metal, manual winding

1945 Chronograph Valjoux cal. 84, 17 jewels, hand-wound, chrome-plated

1947 Chronograph Valjoux 72 C, 17 jewels, stainless steel, full calendar

Source: "Koimaster" on "watchlords", Wolfgang Salm "Wristwatches"