I skimmed two vintage drum books I have.
The one thing I found that seems about right is WFL drums made between 1938 and the late 40's. They look similar to the "Victorious" line WFL made in this time period. The picture has metal lugs rather than wood ones, so it was most likely made between 1938 and 1941 (given after 1941 metal use on domestic products was limited due WWII) or after 1945 (when they returned to metal lugs) but before 1949, when that lug design was replaced.
But of course, without more pictures, it's difficult to say 100% sure.
The finish also matches pictures of WFL drums from 1938, but of course, Ludwig used that finish much later too.
I too am stuck with more questions than answers at this stage ,and no one left to ask.
Trust me, I know that feeling all to well.