Master cylinder color on S1 E-type

All,

I have spent a fair amount of time analyzing the detail of 3.8L brake
boosters and still don’t have a good feel for what color the brake and
master cylinders were when they left the factory.

I seen spots of black paint on some, no signs and signs of plating on
some, and everything in between. As a consequence, I’m reluctant to
deduct any points on these, as I’ve seen everything.

Does anybody have a firm fix on what is actually technically correct?

SK
62 OTS