Welcome to the Forum, although I am new also.
When I go to the local salvage yards I look at every 81 to 91 Chevrolet truck or Blazer, Suburban and buy the good condition doors, fenders, wheel wells, hoods, tailgates. I will never run out of replacement parts because I spend the time and source the parts when they are starting to become scarce. Have a definite affection for Chevrolet, GMC trucks.
Some parts will never be available again. If you find a replacement you may need to either pay for the replacement and help fabricate that part, or fabricate one for yourself, or use an alternate part from another Brand of Vehicle.
Think it is hard now, wait 5 more years. When the Federal Government had buyback bounties on old cars to buy new Vehicles to promote helping the car companies, indirectly killed the salvaging of parts for serviceable cars and trucks because those vehicles could not be salvaged but scraped, melted. Military Vehicles are even harder for parts because of the special need to be resilient and interchange with MV's.
The parts may be out there, you will have to continue the hunt, be patient. Good Luck