Strange case-back on a Le Jour dive chrono, any ideas?

I've never seen them with anything but plain backs w/lettering. And the "2002" is odd--given the age, I have to assume this is a model no. not a year. What do folks think?

What does the front and inside look like?

Valjoux 7733 inside

I have seen a few of these Le Jour with this generic skin diver chronograph cases a lot of lesser known brands used in the 60s and 70s.

Otherwise the more common Le Jour with this dial where in this case:


I don’t know if your is just a generic case with a Le Jour dial or came from Le Jour like that and they just used the same casebacks as the other generic cases did.

Valjoux 7733 inside

That's a very good point.

such a cool piece! but yes, this coud be different dial.

Mystery solved. The case, a ref. 2002, was used by a number of manufacturers in the mid to late 1960s, including Ollech & Wajs, Jenny, Orfina, Tressa, and a host of others. It is a proper dive case, including a screw-down crown and water-proofing to 20 atm (so not a "skin diver" by any stretch). And damn, it is rugged as all get out--on the wrist, it feels the epitome of a proper tool watch. Tremendous variation in dials, lettering, bezel (I have another ref. 2002 with a gorgeous blue bakelite bezel), but the backs are typically the octagonal design, some with just lettering, others with the classic "spear-fisher" logo. The majority are specced as dive chronos, but a few are done as yachting chronos, generally differentiated by the five-minute red or 5/10 minute red and blue sectioned minute registers, a bezel demarcated in hours (to make up for the lack of hour sub-dial), and sometimes additional markings on the dial (again, my other piece has no less than four different dial demarcations).