If you buy a vintage piece and it happens to have a badly scratched caseback, is it easy for a watchmaker/repair shop to replace the caseback with one of the same size, even if not from the same brand/model? It's sometimes not easy, I imagine, to source a very specific brand's caseback (particularly a defunct brand). But if a watch measures 36mm, are there generic 36mm casebacks that will fit most watches? I get there is a difference between a simple pressure caseback and a screw-on, but within a basic type like the screw-on back, is it easy to swap out a part on one watch brand with a generic piece?
And I guess I'd ask a similar question about bezels--easy to replace the 40mm bezel on a vintage watch with a generic 40mm bezel, or are most watch cases built so that they need the specific bezel intended for them?