Singers really are lovely. My mother's Singer head looks exactly like that one, except hers is motorized. She bought it in 1944 when she was in high school and she used it so much over the years that she's had the motor replaced three times! She has that buttonholer attachment, too - same black box and everything. I know how to use that one! The rest are a puzzle.

I'm in the same boat as you; I have a Wheeler and Wilson treadle machine with a whole drawer full of those mysterious attachments and no idea what to do with them. *g*