As mentioned, I sent the parts to RestoRick to have him chemically test the parts for the correct plating as my parts had oxidized enough to make the right plating type hard to determine.
The main rod, spring return bracket, the actuator bracket, and the hinge arms were all black zinc.
The roll pins, flap spring were clear zinc.
The end caps and flapper door were air cleaner lid orange (I used RestoRick's PPG Concept paint, matched very well to the original color)
If you attempt to do the same with your's, make sure you take LOTS of detailed pics first as it is very easy to install the parts in the wrong order/backwards and it is a pain to knock the roll pins in and out without doing any damage to the fresh plating
