This case is a bit unusal, I would describe it. And I wonder about the numbers on the case back.
The movement is about 1952, the dial is look a like the 40s. Are the 4 digits on the back a reference number?
Has anybody ever seen such a package? It is a really nice watch but is it legit or franken?
I'm curious.
Case size is 32 mm.

 

Not a common shape, but not super unusual either. Also, doesn't seem out of character for the late 40s or early 50s. I think #32 in this French catalog from '49 is similar - https://www.vintagelongines.com/index.html#brochure17

The four digits on the back should be the batch/order number (identifying the group within which the case was manufactured) and 35 should identify this specific case within the batch. Overall, I think it's a nice, legit watch.

 

I have similar markings on a mid forties Longines case.

the 2 digit number is repeated on one of the lugs on mine, I suspect so the back and case stayed together during manufacturing..

 

Hi out there,
thanks for your meanings. In the 50s you can't find that batch number on the lugs. That was usually in the 30s/40s made.
I thought the 4 digits could be the reference, but that would be a strange number range beginning with a two. But I also have
no doubt that it is a Longines case. Interesting for me, how you identfied it. Thanks a lot.