wiring looms I know are longer on E-bodies but for the life of me can't remeber if originals were 7 or 9 hole.

battery to radiator support ground bolt is clear zinc not body color

master cap I think was originally dark grey phosphate on 71's with drum brakes.

Also, in regards to the horn bolts, I've seen both these dark bronze AND black phosphate plating on originals . so imo, both would be correct.