Well, if nobody else is gonna answer, I will!
I hit up the first vendor I could think of; based on your likely state of residence (hey, even an old guy like me could spot that red-on-copper "Historic Vehicle" plate
). If you're anywhere on the west side of the state, it's not that much of a drive...... take the wife/girlfriend/"main squeeze" to see the bright lights and grab a u-haul trailer to take the sting out of shipping charges!
Based on catalog links in
THIS PAGE; you're looking at $200 for repop sheetmetal - add 40 bones to go "original Ford tooling" on one piece. Me, I can cut, weld and grind a lot better than playing with a body dolly; so this would be a no-brainer if it were my car. If nothing else, I'd sure spend the 39.95 to not try straightening out that rear valance!
You're lucky, you're working on the generation of Mustang with the single-most plentiful supply of replacement sheetmetal resources. When you're done looking at the 64-66; take a gaze at the pages devoted to 71-2-3 Mustangs. After feasting your eyes on the parts that
aren't available; realize that each part you
can see is just one more part that you can't get for Mustang's same-year "orphan cousin" from Mercury. Basically; if it's on the outside of a '71-73 Cougar and nomally painted body-color..... it's original sheetmetal only available off a junked car.
