Just a tidbit of information for some of you.
I have a Singer model 66-(4?) and a model 66-2 treadle machine that I have been trying to get attachments for.
On my way to the dealer to have my walking foot for my Janome fixed (which I paid $33.00 for), I stopped at Joann's and bought a generic walking foot. The woman there told me to save the packaging and receipt in case it didn't work on my vintage Singers.
Well, it works perfectly on the Vintage machines and was only $15.00. Although the part isn't "vintage" I now can use it on my vintage machines which I love sooo much more than the Janome.
I am thrilled that it works as the stitching on the vintage is so perfect!
Hope this info is of value to some of you out there.