I have a 1971 Charger with power disc brakes(Midland-Ross type booster). Should the power brake booster be painted or plated? I have seen some with paint and some plated in gold cadmium. Could painted and plated boosters both be correct? If that's the case, does it vary from assembly plants. What about the master cylinder? I have seen painted and natural cast master cylinders with plated boosters, and with painted ones.

If you mean the pancake booster, then it's plated and there is a decal that goes on it.

Booster and M/C cover plated. Used RPM on the body of the M/C

Looks nice but that's an aftermarket master cylinder.
NOS 71-'74 master cylinders I've had were coated with a gray coating, body, bale wire and lid. For lack of a better description I'd call it a parkerized finish.
Only exceptions I've seen were the carry over "9191" disc brake master used on '70 and '71 hemi E and B bodies, and the 72-74 manual disc brake master cylinder, both of which were painted black, including the bale wire and cap.

This is an NOS master that I put on my 71RR. Don't know what the finish is called?? From my research that's what I came up with. There was no gold cap on 71's. Also the brake booster was gold cadium plated not painted.

My M/C is not original to the car. I originally had drum, now discs. I am aware of he colors,etc but went this route to make the booster and wiper motor look similar

I guess it looks like I need to refinish my master cylinder and booster. They are both original to the car, so I won't be worrying about finding correct pieces. My brake booster is in really good shape with no rust or any kind of pitting from what I can tell, its just painted. If the plating is good under the paint, anyone have a suggestion how to remove the paint without damaging the plating?

Just take the booster apart. 71 boosters are easy to disassemble and reassemble.