Macybaby, Thanks! What an education this is for me. I got a back clamper a couple of months ago (lotus hand crank), and until then I didn't even know about back clampers. The number of variations of some of the attachments is interesting, if a bit confounding. I guess Singer was still working out their design. But I now understand why a lot of the adjustable hemmers I see are in two parts, or missing the guide. I love the flange hemmers with their adapter foot. I wonder if these are the first version of "snap on" feet.
Your treadles are beautiful. A treadle is on my want list. But I have to get rid of a bunch of stuff before I can fit one in here. Thanks again for the pictures and detailed descriptions -- I'm going to use them as a reference.