I don't know about all of that, Deve. I am currently driving an old restoration at least 15 years old with 5-8 pounds of fiberglass and some kind of body filler in the cab corners, and you cannot tell that they are not original metal from the outside. No rust. The dude that did that repair had some real talent, all be it unconventional.
You may want to read the entire thread before lecturing a guy on how to make a show quality truck. He is not going that route.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission