The first thing you need to buy is a Tub! Not sure I've ever seen a pre 79 that was that bad. Good luck with this!
I apologize for photobombing the Jaybird1's thread....
How my CJ5 looked in 1996:

The automakers back then, installed rust at the factory. Corrosion resistant steel was years away from being used. Way too much work to repair.
New tub:
