Heck if you're in south west OH then we aren't to far apart. I had good luck with the cold galvanizing compound, but I usually use rubberized under coating though. I also have learned about some oil sprays for keeping seams and whatnot from rusting but have yet to try them. I coated both Broncos we have with Rustoleum Black paint the 85 was a very through job that got sandblasted, primered, and painted. My 89 just got a good pressure washing and a coat of just paint with a hvlp sprayer.
Yeah, I'm not too far from Indiana. As far as the oil sprays, is one of them Fluid Film? I've seen it mentioned in the forum here and it sounds like it may be promising.