how bad is bad ?

If I were you and having read all the posts I would salvage what I could off both those cars and find a rust free western body and build it the way you want. Have you been watching the prices escalate for the nicely done clone cars. You could do the same and I don't think you would ever lose money if it was done right. Besides why beat yourself up dealing with all that rust when the labor could be spent restoring your new rust free body? Of course my advice is worth exactly what it cost. It's too bad those cars were parked by the ocean unprotected. Good luck! Dan