I thank you for your comments guys!
I rusted (or browned) most of the larger metal parts - some exceptions were the lock plate and the barrel wedges and escutcheons.
For the rusting process I started with a diluted solution of Brownell's Classic Rust Blue, about 10% of it with the remaining 90% of the fluid 50/50 denatured alcohol and water. My theory is that the alcohol may help cut any oils missed in the prep process, and if not it doesn't hurt anything. That dilution was applied for the first 3 or 4 rustings, and after each rusting the metal was carded with a Brownell's carding brush mounted on a 1750 rpm motor. At this point it doesn't look like much progress after carding, but trust me, the process is working. I normally do at 3-4 sessions in a day if conditions are correct.
After a small rust grain was established, I increased the amount of Classic Rust Blue to about 25% solution.
(All measurements were done by eyeballing so they are approximate.) and continued on for the next tow or three days. At the end of the day, I card the metal and do not apply another coat of liquid until the next morning. So I do the last carding at say 5:00 pm, check on the metal and likely card it again at 10:00 pm, then apply solution again in the morning and repeat the cycle.
I find that if I quit applying solution just
BEFORE I reach the desired color, then continue to monitor the metal and card it as needed (at this point I may use a rotating brush, a "toothbrush" style carding brush, heavy cloth such as denim or burlap, or a piece of brown paper bag) - depending on how much rust is present.
I find if I stop applying solution early I do not get much after-rust when the metal reaches the desired color. I can always apply another coat of solution if it doesn't get where I want it in a reasonable amount of time.
When I am totally finished with the rusting process, I scrub with a 50/50 solution of household ammonia and a toothbrush or rag, then wash in dish soap and hot water, and last a hot water rinse.
Here are a few random pics of the browned metal ( I will have to get a good photo of the barrel, I haven't taken on yet.)
The triggers, barrel wedges and escutcheons were niter blued at approx. 650-700 degrees. Sorry, not the best images here....
And the lock plate was given a Bright English Charcoal Blue in order to help preserve the tiny, detailed engraving.
Still applying oil to the stock... the wood finish will be the next subject posted.
Thanks for looking,
Curtis