Greg, go to Wal-mart and pick up some rust converter in either spray can or bottle. Wipe the body down with alcohol then follow the instructions on the lable. It will kill the rest of the unseen rust and turn the metal black. Make a good base primer and then use either POR or Eastwood's rust encapsulator to seal it. They are both sandable.

Use a big enough catapult and even pigs can fly...remember nothing is impossible, impractical yes, but never impossible.