The quarter panel was replaced and repainted, so that paint is not original on that particular panel. Either have someone who is experienced with /restoration/survivor type cars repaint the quarter with single stage paint to match the door, trunk lid, or if the majority of paint on that quarter is decent and a good colour match, have it spotted in along the top surface and call it done.

Hard to see from a photo, but I'd be inclined to spot in the top and leave the 40 year old repainted quarter as is unless the paint is failing on the rest of the quarter badly.

Buff the two scuffs off the side and leave the side as is

Awesome Dart by the way!