I have the small diametre generator with a chunk missing out of the pulley. It still works, but I have to change belts more often than I do my oil!

Yes, every vendor claims their later, non-threaded, keyed pulleys will work for a 1939 tractor, but if it has the original "small barreled" generator on it, they do not.

Tim Daley had a bunch of the correct style pulleys cast several years ago. Does anyone know who has them now?

Tim sold almost all of them before he died. He was keeping one to go to restore his father’s ‘39. He was supposed to sell me one about a month before he died. Never did. He lost his storage and sold a lot of stuff. I contacted the guy who has his father’s tractor and he was going to talk to Tim’s wife. Still waiting to hear back, been a long time. I’ve since had mine repaired and picked up another complete generator off a ‘39.

Thats pretty much what happened to me- he still had a few of them at that time and was going to sell me one, but he could never find them. After about 6 months of trying, I gave up. I later found another cast pulley of the same belt-width and diameter and will either bush and broach that to fit my generator, or cut a piece out of this pulley's face to fill in the missing chunk in my original pulley.