Pella Hinge Shoe

I have Pella casement windows approximatley 30 to 35 years old. These type of hinge shoe broke on a right and left hinge window.. I found out from Pella manufacturer that their supplier part number is would be a 7757-001 (left roller hinge shoe) and 7758-001 (right roller hinge shoe), which looks like the numbers (I can read) on the window pieces I have. It looks like your Pella Hinge Shoe Pair Product Code: 39-371 and look to be the same size. Do you think these would work? I have a window contractor that thinks he can replace just this shoe, vs. Pella says they only sell the whole hinge assembly and they don't recognize your part number.
Thanks
Annette