Rust Question?
 

I was wondering if this rust might be a problem? It seems that there might be rust in between the two layers of metal? Anybody else have this problem? What do you guys suggest to fix it?

That wouldn't be a hard area to cut out and weld in a panel from a donor vehicle. If you are going to use it, blast it and douse it with rust converter or Oshpo, Chemprime, etc.

Unless you're building a show truck, scrape and sand and wire bush to remove all of the rust you can, then use a rust killer, a good primer and paint it. It doesn't look terrible. Good luck, Scott