Is my rusty 68 Barracuda salvageable?

I've driven a lot worse in my day, if you don't care about it being perfect get it running and cruise the wheels off it as you fix one thing at a time. IF you try to take on the whole thing at one time on your first restoration, you will fail. You will do what everyone does, disassemble it and walk away till you lose interest. Only way to maintain interest is to drive it while you fix it. it will never be more than a driver doing this but that is what Plymouth built them to be, driven.

REALLY good advice.
Don't get discouraged. From what I see you will get interior experience, body work experience. At this point you have nothing to loose to keep working on it. get it mechanically sound, drive it and like searcher1990 said, don't take it all apart, just fix one thing at a time.