There was a time when all sorts of creative, albeit unrefined, methods of rust repair (we use that word loosely) were to simply cover it up with fiberglass, a chunk of sheetmetal screwed into place, ...
That new project truck is begging for you to restore it to its former glory. Well, if that project is a newly purchased 67-72 C-10 or one that you've owned for years now, some type of cancerous rust ...