I’m not even sure these things were surface hardened to begin with. I’ve got an old worn set somewhere I can check out.
A variation of Jerry’s idea: Might be able to do the same “flip and drill” concept, but apply some sort of high tech (application correct) epoxy or such to fill up the old grooved out areas. Sand back to round with some emery cloth. Probably last a long time if you make sure they get proper oil supply.
