I have a friend that has a older Kubota. It has a LB 400 FEL on it . He is trying to replace the seals in the pistons and it sounds like its a costly adventure. the Pistons are $400 -$500. He Bought a seal kit for 40 bucks and that did not go good. What is the cheapest route to go ? can they be replaced by a after market piston? Thanks Roger