well, we went for a drive today and happened upon a garage sale - and tucked up against the wall was a set of irons!!! - with the metal Pitman rod!!
DH has already started the restoration but even before he did anything he could 'pedal' it with one finger!
No top but the original screws were dropped in the holes from above so they are still with the irons! One wheel is missing tho. I'm thinking maybe the 99 for this? or maybe one of the zigzag machines - I don't have anything like that set up - the only working treadles I have right now are a back-clamping 66 and the Pfaff.
We have another set of irons but it has a broken wood Pitman rod - we do have the instructions on how to make a replacement.
Oh yea, this set today was a whopping ten dollars.....