What year and car are you working on, and which power booster do you have?

 

I can show you my car's, but whether or not it is correct, I do not know. Maybe someone can at least point at things on my car's brake systen and tell you what it right and wrong.

 

In the case of Hemis, they used the Kelsey hayes dual diaphragm booster, and were painted all assembled. If you look at protected areas, they were pretty much gloss black but it was not a high quality paint and there was minimal prep so the gloss level was like the paint you are going to use and it did not last long. These parts were not painted to be in a car show, it was mainly just to keep corrosion at bay for a short while. For non K-H booster applications, the master cyl and booster were supplied separately and had different finishes.