When I'm rebuilding them for resale, I normally just replace the rollers and paint the housing. I've tried several different methods on the rollers and they all end up looking like crap after a few months.
“The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed.” ― Robert M. Pirsig, Zen And The Art Of Motorcycle Maintenance: An Inquiry Into Values