Plenty of leather treatment application and some kind of leather paint may bring the wheel back to half decent condition... but IMHO, it is not worth it. This maybe your other option which I think is the better way to go:
http://store.yahoo.com/afterthoughts...eleur2col.html
I've had wheelskins on my other car for 3 years now and it still looks and feels great with nothing more than light coat of leather conditioner couple of times a year.