Hi guys, I need some help identifying the correct caliber on my watch. I found that it is post 1939 according to the reference numbers on the movement, but I can't find any other reference that identifies the movement on the watch. Sorry about my igonorence but I also never saw any omega like this one, with a squared movement on a round case, so any information you have on what might be this watch is really appreciated Thanks for the help!
R17.8 SC from early '40's. Came with 16 or 17 jewels. Caliber 310 . See if anything is inscribed under the balance.