"KK is considered the go-to double gunsmith in the NW."
I put over 1,000 rounds through a set of barrels and sent them to Kearcher for a rust blue. They were returned nicely blued but with other issues....including, but not limited to, 4 inches of rib separation. He disavowed all responsibility but offered to repair them for $90. I declined his generous offer and sent them to the shop where(I was told by an employee)Turnbull sends his. They were made right again, quickly and very economically.
Keith told me this story some time ago. The rust blueing process cannot cause rib separation. How do you figure he caused your rib to come loose? The only thing I can think of is water getting inside the cavity, turning to steam, but for that to happen there has to be a way for water to get in and no way for steam to get out.
I have had Keith do a lot of work for me. He is courteous, prompt, and reasonable. He is a man of many talents so he doesn't send stuff all over the country like some other guys, at your expense plus markup. The only issue I have ever had with Keith is he neglected to dress the muzzles on a set of Greener bbls he browned for me, and they needed it; and I have heard from another customer that Keith does not neutralize with alkaline solution after browning, just water. Thus if you don't oil your bbls well sometimes they continue to rust. But I can't say I have had this experience and I have had him do over a dozen barrel browning jobs for me.
Keith is a chemical engineer so I very much doubt he "used acid flux", other than for tinning. I'll ask him next time I see him.
Keith runs his business and I run mine. No relationship other than arm's length. And I send stuff to other guys as well.