I'm sure to hear some disagreement from others but IMO Blueing became popular during the Civil War when people noticed that most of the long guns and pistols were blued. In the public mind it became the look of a NEW MODERN gun and the industry never went back to browning. (From a production standpoint, it is a lot faster to blue a gun than to brown it so this coupled with the publics idea of what they wanted led to browning almost dieing out.)
By the way, Blueing was popular in Europe back in the late 1500s thru the 1700s. IMO Browning really became the more common method (in America) when American Gunsmiths started making their guns in the good ol' USA.
Any place selling "kits" and components will have Browning solutions. Try Dixie, Track of the Wolf, Muzzle Loader Builders Supply, Tenn Valley Muzzleloaders, Vernon C Davis (I see this is for sale), Pecatonica Rifle, and many more places.