New, to me, M20

[big gear head]

The new input shafts are not holding up very well, so either repairing yours or finding a good original replacement would be my choices. There are 2 ways that I could make it work. I can put it in a cylindrical grinder and grind it down past the rust and then make a new custom pilot bushing for it, or cut it down and weld it, then grind it to the original diameter.