i recommend sand blasting. the metal on these trucks is heavy enough not to warp. of course you need a blaster who knows his stuff with any media or they can warp angle iron with dry ice. i sand blasted everything on truck, in three stages, as i needed the parts, bed, cab and everything else.
be ready for surprises. i was totally shocked as my truk had been wrecked, probably in the 70s and bondo'd up rather well. i've driven apache trucks since the early 70s and know where to check for rust. over the headlight buckets was spotless. turned out that they had put new fenders on the truck, everything else was caved in cancer. i drove truk for 20 years prior to the resto.
i sprayed everything with epoxy asap. no prep needed for sand, other than blow off well and wipe down with w&g remover. harbor fright gun is fine for this, buy a couple on sale if possible. if you are fast and can do all the bodywork before rust comes back, that works. i'm in a more humid section of the country. if it's gonna be a while, epoxy now or spray the bare metal down with
por15 metal prep, i've had good luck with metal prep for storage of bare fabrication metal for truk
definitely remove any trim. disassemble everything, you don't want to disassemble it later to find rust under whatever. leave no screw untouched
this is my drivers fender after blasting. probably an inch of filler in parts that i never knew about in 15 years of driving it. door and step were also damaged, not to this extreme