I was just looking at this youtube video and it spoke of the plastic protector on the rear bumper, for all the Sport Furies it was color coordinated with the vinyl roof but on the GT it was matched to the color of the stripes, interesting.
I had a similar experience with my 69 Sport Fury. Black pinstripes but a white vinyl top. I thought something was wrong because the car was never painted so I thought someone changed the pinstripes. I researched it and found that for sport fury in 69 the pinstripe matched the interior color, not the vinyl to.