Hello - as the title states, I'm after a movement ring for an early straight-lug seamaster. Pic stolen from the internet:

 

Are there different rings for a 501 caliber 2913 vs a 552 caiber 14755/165014.

 

I’ve been trying to figure that out, but can’t find part numbers (tried cousins, Otto, Jules borel list). The 500 and 550 calls are the same diameter and I think the cases are the same, so it should hopefully work. Do you have one I can check in my case?

Thanks!

 

I have no extra but looking at 2913 and 14755 pics the rings do appear to be identical. Good luck!

 

I may have one...I'll look thru my parts.