66 Dart Trunk Extensions

I thought Dart 63 to 66 Dart would be the same for this. Not sure about Barracuda.

Sherman's used to make them, but not seeing them on their website anymore.
http://shermanparts.com/ecat/base/dropdowns.php?make=DODG&model=DART&year=1966

I think they supplied to Layson's. Not sure if you can still get them from them or not either.

Other option, find one in a junkyard that has good ones, or Make them.