It's hard to comment on the case without some more pictures but it's quite possible that the case was moved from a nicer sportivnie, impossible to say. These cases can be re-chromed but that would be obvious.
From what I can see, the movement looks fine. Since this is a common movement from that time any little differences could be chalked up to period repairs/replacement and could be reversed.
A positive for this one is that on the dial the red star on the "flying bomb" has not been re-painted as is often done by sellers "dressing" it up.