After years and years of research, and documentation on the American Colonial Rifle, And this is only for the builders who want their rifles to look the same as they did when purchased new back in 1760-1770. This is not for builders who try to replicate 100s of years of patina. #1 barrel and lock left in the white. Browning these parts didn’t come about till the beginning of the 19th century, although there is very rare instances where gunsmiths experimented in this new procedure but It didn’t become mainstream till beginning of 1800. Bluing was available but not as common as just in the white.
#2 Brass was bright and shiny. Brass was very expensive back then, and it was very well taken care of #1 by the gunsmith who wanted to show off their work, #2 the owners who wanted to protect their investment. Again this is not for the builder wanting 100s of years of patina on their rifle, but more for a builder wanting their rifle to look like it did when bought new in that time period.