A few things I want to add as afterthoughts to my rebuild: first, I did not use distilled water for the boiling water rust bluing bath, but rather used spring water from our water system. I don't know whether that contributed to the nice 'between brown and blue' color to the metal finish or not.
Also, the rusting did not neutralize after the use of ammonia, and may have helped to continue the rusting process - some folks would say yes and some no. Either way, on my next build I will neutralize with washing soda and then a thorough soaking in water instead, followed by a saturation of the metal with diesel motor oil rather than the Corrosion-X product.
As a side note, for day-to-day protection of the exterior metal I use Ballistol. For the interior of the barrel I use Barricade.
