If you grind the crank and put in new bearings, seals, rings, you're looking at about $800 last time I did it.
Florin Tractor, California.
I have also had those keyways welded and recut, of coarse they get cut back to exactly where they were or else. Even the had the area where the gear fits built up and reground, the gear was loose and just slid on before.
Check the for sale section I think Gemdozer has some pony parts still.
I have a couple of pony motors tore apart and might be able to help also