I always look at vehicles like this and remind myself that they were once brand new, shiny pieces of mechanical engineering. Somewhere along the way, their stories took a turn where function was more of a memory, and neglect became their new reality. I remember as a little kid crying when I saw an abandoned Corvair being towed away from near our house, headed to the scrap yard. I felt like it wasn't fair, and that the car deserved better than that. Even then, I was a real car guy.
I think the rigs in pic #2 and #4 definitely are salvageable. The one in #3 is hard to tell. And poor #1...well, let's just have a moment of silence, shall we?