I'm always keeping an open mind and trying to learn. In my side business as a flight instructor there is a saying "a good pilot is always learning". I would add, a pilot who thinks he knows everything should not be allowed near an airplane. Too dangerous!
Same goes for restoration research. That's why I get so put off when someone argues with you and says they are "sure" of how something was 40 years ago. I wrote the only article written so far on OEM Mopar master cylinders in '05 (April Mopar Action), based on my research having an archive of original OEM master cylinders to examine at my old work (the only one of this style drum master cylinder we had was the newest sample, early samples had been discarded during a housecleaning several years before I started there. ) In it I said that drum brake master cylinders were bare metal. Soon after the article was published I came into possession of a vintage core, and when I started to clean off the surface rust I found black "ecoating" on the casting. Several months later I bought some early NOS samples that were black ecoated.
I would like my article to be 100% accurate but evidence I found later tends to lead me to believe it was not completely accurate.
I am just a scholar here on this subject, I have two Challengers, but they are both disc brake cars. I know what color their master cylinders should be! I just am interested in knowing for certain what these drum brake parts were "back in the day" and when I have brought up my evidence I get ripped on. I give up, she's a witch! The world actually is flat! Please don't kill me mob, I apologize and please forgive me for being stupid and questioning your consensus! The mob rules!
From what I have learned over the years, all '70 boosters were originally black. But I am open to new information and finding out if there were any exceptions to that. Certainly many '70 boosters were painted black. Were 100%???