[cleszkie]

You can't fault these trucks for their rust. They are over 40 years old. And if all the previous owners had periodically opened up the drainage holes in the body panels, rather than let leaves/dirt/animal carcasses/bees nests/etc. accumulate over the decades and hold in moisture, there would be a lot less rust on these rigs.

Its sounds like you are doing the best you can to deal with the rust. But I would also recommend that you now periodically check your drainage holes. Even the best rust inhibitors will eventually lose the battle with water if it is allowed to sit against it for a long time.

On a final note, the old timers may have had the best solution for rust prevention. Cover the truck (top to bottom) in used motor oil! Sounds strange, but I have seen trucks treated this way survive very well in the rust belt states.