He sent me the part and it is not exactly the same but very very close.
I put in in my vice and it seems to work very well. He said it was
made of Bronze, I think silicon bronze. I paid him $15 which was the
price on the parts list he sent me. If it continues to work well, I
might buy another as a spare. I would rather have a bronze part to
wear out then a steel screw. Thanks again for the tip on where to get