I acquired this watch awhile ago, it's a 21 jewel Bunn special in an Elgin case. This would not have come in this case as there are other case screw markings but I was wondering if a specific Elgin would have been in here. If so, which movement would have been correct? It is a very nice case but I know little about Elgins.

Steve

and from the back.....

and the case back markings.....