You could probably fix it for nothing, Bob, by fitting two roll pins, at right angles to the original one, at the two ends of the hub. It would be twice as strong as when it was new - that might be strong enough. There's a good chance you'll find movement in the roll pin at the other end of the shaft, too. If so, you could fix it the same way. To get keyways cut in two hubs and both ends of the shaft seems like it would cost at least a couple of hundred dollars.
