Technically, these are listed for the 67 GTX, but will fit and work on the 64-65 Barracuda with just a LITTLE sanding of the edges.......
RS-80S, $69.95 plus S/H....Rocker Molding Clip Kit - 20 clips (For Plugs find part # GM-1510P)
GM-1510PS, $5.50, Full set of (10) round plugs / centers...