OK, I'm doing a crazy nut-bolt frame off restoration on my 72 Cutlass Supreme. I need help in identifying correct plating colors for the parts I have shown in the pictures. The bracket appeared to have been black but have seen some done in gray phosphate. The vacuum diaphram may have been clear zinc but have seen in gold. Also want to know about the color for the bracket holding the transducer to the wheel well and brackets for the carb rod. Someone must have an original unrestored system or is knowlegable enough that can help me.

Thanks,
Dave

 

I restored an original set of these.
The brackets were low-gloss black but were very nasty. It did not seem like paint as most had come off. They cleaned up easily though.
I DO know the servo itself was clear zinc plated, as the inside was still good.

I have a NOS servo and it is also clear zinc.

Now I also restored another servo (which was a Mopar part, almost identical to a later Olds servo) and it was gold cad.

I have a thread out here called "120 on cruise control" with pictures - maybe they will help you decide on the brackets.
You would be amazed at what I used on the old servo!