I used to do engraving for Bill Gillette. Big Ridge Gun Shop on Parma Ctr Rd, Hilton. His orig shop was on Big Ridge Rd in Spencerport.
Most of the engraving was recutting work,,w/the occasional custom job.
Recutting lettering on pieces to be reblued. Sharpen up the polished over lettering or replace what was missing.
Small jobs but at the time I was happy to get the work. This was 70's and 80's. I just started engraving in the early 70's.

I had him do the hot blue work for me as well on other engraving work I was doing.

He used to mix his own bluing salts,,not liking the results with DuLite or Brownells salts.
I don't know if he had a background in chemistry or not.

He started using the 'trick' of adding Cyanide (Potassium Cyanide) to the hot blue salts to render them harmless to SxS and O/U bbl sets with soft soldered ribs.
I did my own rust bluing so I never had a set hotblued. I was always skeptical of the process, but he said it worked.
With the addition of the cyanide to, I kept clear of the BluingRoom at the shop!
He did tell me he lost a couple of the BarnCats that used to hang around the shop.
They would walk around in the Bluing Room and along the edges of the tanks in normal cat behavior. Then do their normal thing of cleaning their paws.

I hope it was quick.

He closed the shop in the 90's. He and his wife (Martha) went 'on the road' following SC, Skeet and other shooting activities. Setting up a mobile shop out of their RV at the locations.
Head down South & SW in the winter and gradually work their way north as the weather and the activities moved around as well.
I went to the auction held at the old shop. I remember buying the second item put up for bidding,,a Parker 12ga for $35.00.

Just some thoughts for you.