There are a couple of things you can do to help put the drum into at least a category, i.e. American, British, continental etc. Get a hold of an s.a.e. and a metric thread gauge and find out what the t-rod thread is and perhaps a few other screws on the drum. Any machinist should be able to do it for you. If it doesn't turn out to be either , then it is likely one of the numerous British threads. Hardly anyone outside of Britain would have gauges for those. Also measure the t-rod heads and see if they are metric or inch.
Try to get a species identification on the wood( if you posted me very sharp closeup pictures , I can tell you) but it looks birchish to me , at this point. Although , imported hardwoods, such as Honduran and African Mahogany and Teak have been used for drums of this vintage most of the lighter wood shells were made from domestic woods or woods that were very close at hand( Scandinavian birch for instance), so the wood can give a big hint.
It is a commonly held belief that German drums and European drums in general have slot head t-rods and American and American style rippoff drums have square heads but this has only been the rule since about 1950 and this drum likely pre-dates that. Prior to 1950 and as you go further back, there was an increasing use of large square heads, historically, on German drums.