My local, trusted, gun shop claims I ruined the barrel without inspection
...Find another gunshop to trust
"...WMD out of Florida says they can Nitrate my barrel to be like new."
...I'll just bet they can,,,
"...I used goof-off and Krudd Kutter to take the finish off. Krud Kutter says, on the bottle "Rust Remover and Inhibitor"
...Krudd Kutter is phosphoric acid (about a 20% soln) It's the same stuff used in most every other over the counter rust remover (Naval Jelly being to old standby,,pepsi cola even before that)
They remove rust, which bluing is a converted form of but do not attack the steel. They leave the steel surface a dull grey appearance but that shines right back up. Usually you get corners and crevices of the parts with a coating of what appears to be rust still attached. That's the residue from the removal process and it cleans right up with a wire wheel or fine scotchbrite abrasive pad.
You won't harm the bore, it polishes right back up nice and shiny with a brush back and forth a couple times.
I used to use phosphoric for blue removal but for a long time have used muriadic acid in a very, very weak soln. Same effect, but for me quicker and more even results. (No leaving it in the stuff over the weekend though!)
"...A did my own test and left the frame outside last night, wet.
Please see the pics. It looks like everything rusted but the barrel."
....Don't know why you set it outside to rust,,but, run it through the remover again, rinse it well and oil it up. Then send it out to the re-blue guy.