Could it be some sort of cowbell clamp? Maybe the double hole section with the wing nut is designed to go over a tom L-arm, instead of a tom.

The section with the black thumbscrew can't clamp to a hoop cause of the piece that's sticking up. Maybe it clamped on to a horizontal rod and the side with the holes held a rod with a splash or something

I am thinking it might be a woodblock clamp. the two holes on the right might go onto an old thin straight stand, then the horizontal bit clamps down onto a woodblock some how :) It seems to have the horizontal supports for a woodblock shaped object

The wing screw is too new for the piece, so the hole may have been re-threaded to make it fit. I don't think this is a part for a drum at all. Old parts even turn of the century parts were never (or rarely) painted, most were polished metal or later on chromed. It could be a Temple Block holder for a 1920-30's Orchestra Pit Console. If this is the case, you are missing parts.