Cool trip. You hit all the high spots. Started on the "Hastings Cut-off" route to SL City, which didn't work out for the Donner Wagon Party, but you avoided the Sierra-Nevada. My first drive from Atlanta to LA was similar. First time in LA, but everything was deja-vu. I had seen every scene before, but in a movie.
When I see photos of people doing extensive rust repair in the northeast or Europe, I think just save years of work and buy a rust-free AZ or CA car and make a vacation of flying out and driving it home. You used to be able to find them cheap, but now it takes more work. Soon after my 1991 move to SoCal, I bought my 1965 Newport for $800. I was amazed to look behind the rear bumper and the bolts and brackets looked new, w/ not a spot of rust even on unpainted suspension parts. As soon as you can, paint all the areas where the factory did a half-@ss job, like top insides of the doors and other hidden inner areas. The outer ends of the lower control arms weren't even painted, just dipped in wax.