72 Duster Quarter Replacement Questions

Look carefully at your new AMD quarters as they probably pretty much duplicate the factory parts. (within reason) Look for the spot welds at the joints and drill them out so the factory quarters are completely gone. Including the joints at the trunk edges. Temporarily hang the quarter using clamps, sheet metal screws, clecos, whatever you have. Look at where you are and what has to be filled in. Pieces that are not visible from the outside can probably be fabbed up by you and welded in.

I understand your reluctance to buy a complete rocker and only use a small section but sometimes that is what happens. Ouch. Using a contour gauge, can you verify that the contour of the rocker is uniform front to rear? Can you buy just one new rocker, split it, and use it for both sides?

But on the other hand, is it better to remove the entire outer rocker, inspect, repair and rust proof the inner rockers and go with 2 new outer rocker panels? Your Kansas car is probably not nearly as bad as the junk we have around here.