We sell used Farmall Cub parts and would like to comment on when to use the old original parts and when to use new. Many of the original parts are no longer made and so there's no choice, but when restoring internals, like engines, etc. it's best to replace worn out parts with new whenever possible. We do recommend replacing pistons, rings, bearings, points, etc. Any parts that burn out, wear out, or break. Cultivator, chassis, and implement parts that are a bit harder to come by, should be cleaned of all rust and painted to deter its return. We clean our parts using sand-blasting, wire brush wheels, and  electrolysis.  Our electrolysis set up is easy and works really well on some of the tougher jobs. We used Jim Becker's Article on how to build our electrolysis tank and it's been in use ever since. You can find his article at cleancomputes.com. It has pictures and a detailed guide for building your own. This system of disolving rust has been a very helpful aid in our cleaning process. We get comments all the time from customers who say our parts look new!