Yes, you're correct that the Pfaff has three shafts, one for the needle, one for the presser foot and one for the walking foot. Here are the part numbers for the feet I purchased from Ultimate Sew and Vac [91-026473-05 and 91-026474-05. here's the link to the page: Industrial Presser Feet* Commercial Sewing Machine Parts
They assured me that they are correct, but they are not, they are completely wrong. Any suggestions? I could take photos if that would help.
As for the Singer I was finally able to get the hand wheel to move, but it wasn't easy. It seems like something is wrong.