Found this watch yesterday, don't let its looks fool you. This thing runs like a champ. Can't get the back open but don't really care to, I'm gonna wear it til I dies then maybe try an find different case for it since the dial is pretty awesome. I'm gonna guess it's a cal 283 but I'm probably wrong
Nice survivor ya got there. Man I would get the movement cleaned and oiled. polish the crystal and hit the case with a jewelry cleaning rag and wear the hell out of it.