I would think that a shop or an individual who has been color case hardening long enough to earn a reputation of high regard in replicating original color will have long ago gone through the 'trial & error' phase where they might have crystallized the steel. I'll stick with the professional who doesn't make such mistakes. But that's why I am asking these questions.
A lot of DT's colors these days are much too dark solid blue and not like the bright translucence that he used to produce much earlier, and much like the Remington Parker colors CJO showed in his pictures.
I know all about the differences between Parker Bros. color case hardening process vs. Remington's processes in later years... I am NOT looking for the chemically done colors such as cyanide which was used by Remington in the thirties and forties.
Methodology about the CC process varies widely. Several years ago when I began my research, I was amazed at the wide variety of instructions available, and the professionals like Turnbull and others don't volunteer info. (I don't blame them). The best examples are Brownell's and Midway, providing very basic info at best.
