dried sandwich spread sealer?

You hit the nail on the head. That is exactly what I'm worried about. But I don't know what putty to use. I'm afraid some kinds of sealers might encourage moisture and then rust. Chrysler didn't appear to have painted these surfaces anyway, but I did find evidence of primer. Please tell me what putty to use. You are solving a big head ache for me and I really appreciate it. Really good replies that have helped from all of you.