I HAVE A SUPER LO-BUDGET OPTION WHICH I JUST DID ON A COUPLE PANELS OF MY 53 MERC. I WANTED TO TEST OUT A PAINT GUT I BOUGHT ON EBAY ($4 !). I TOOK SOME PLAIN OLD SATIN X-O RUST, MIXED W/ MAYBE 25-30% ACETONE AND SHOT THAT. IT CAME OUT PRETTY DAMN NICE FOR $10/ QT PAINT AND WILL BLOCK RUST MUCH BETTER THAN PRIMER. ONE THING I DONT KNOW IS HOW LONG IT WILL LAST. NOT A BIG DEAL THOUGH, $15 TO RE-PAINT IT!