Thanks to Peter Bernard for scanning and cleaning up this photo.
UPDATE: My blogging colleague,
Owen Woods points out in comments that the box in this picture is a
schwyzerörgeli, a swiss variety of accordéon. I had thought this was a type of club accordéon, but looking at the left hand side of this box it is very örgelish. Woods did a an excellent piece on the schwyzerörgeli
HERE.
UPDATE TWO: I was excited to read the following comment from B.V.:
Hello, this is perhaps the accordion club in Zurich. I am looking for material on this club Zürich-Wiedikon. If you have any other photos, I'd be happy to receive mail from you. Maurice Thöni have led the club in the 1940s. Sincerely B.V. http://www.notrehistoire.ch/group/maurice-thoni/.