Those old puzzle boxes were made for short shank machines, and they will fit on newer machines if you want to use them. But I think Singer went to other box types in the very early 1900's. There were some early 66's that took some very similar attachments that were back clamp. Singer never issues a back clamp for the 66's though.
The puzzle box sets were primarily for the early 27 and 15( IF) machines. But the good thing is that much newer short shank feet will work fine. The only stuff that is more specific is the underbraider and shirr plate (works with the ruffler if you want to do gathering in the middle of the goods).