Have a 1958 vintage OC 4 (no reverser in the tranny) in my Fathers estate. One cylinder burns enough oil to foul a plug every few hours. The thing jumps out of reverse, otherwise I believe the tranny is okay. It needs new rear sprockets and the tracks are worn past the point of being able to pin and bush them, so it will need new tracks. About what is the thing worth? I would like to restore it myself. My siblings will require that i pay what it's worth, but I am not going to overpay either. Or should I simply call Zimmermens and sell it to them for parts? Thanks.