Hydraulic shocks can be rebuilt. Here's a guy that can do it.
OEM and custom shock absorbers, USA made coil springs and leaf springs, steering dampers for all makes and models. Rebuild service for original hydraulic and lever action shocks. Rebuild service for steering gears and power steering pumps
A-1 Shock Absorber Company
365 Warren Av. unit #101 and 109
Silverthorne, CO. 80498
800-344-1966 or 970-513-8283
http://www.shocks2springs.com/