Hey Chuck! Full restoration might prove to be difficult, but I think you should be able to do a pretty decent rest-mod. Most parts used by Clark were off-the-shelf parts from other manufacturers. For the most part, only the transaxle, axles and hubs and some interior parts were made specifically for the Cortez. Some things might require a good parts house who can look up the old part reference numbers.
Good Luck!
Moose