The hard part about buying a truck this old is curbing your enthusiasm. It is easy to get all exited when you look at one that you can't see the trees for the forest. Typically a few rust holes here and there are just as difficult to fix as a whole lot of rust. So if you do not want to do a lot of body work, open your eyes and be picky before you pull the trigger. Brakes, steering, drive train will likely need to be gone over regardless of what the seller says (sometimes they don't know the true condition of the mechanical items).
Carl