I'm about to finish my floorboards in my '39 Ford two door sedan. It's channeled over an S10 Blazer frame so I made my own. They are welded in and seam sealed. Should I just do the Rustoleum thing or is some other paint better? Should I put 1/4 inch insulation on them? I also have to old insulation and from the S10 Blazer if something like that would do. Thanks in advance, Rod