For now I am going to slap on the original bumpers belonging to the '65 Formula S (don't have the means to restore 'em right now). I can shine up the chrome and little beforehand, but what to do about the "hidden" rust on the inside? Thank you.
Knock off the big chunks, scuff up the surface rust with some sand paper or Scotchbrite and shoot it with some rust converting primer then paint if you wish.