A guy on the forum did a 10/22 barrel for me years ago...in fact, it wasn't THIS forum, but one of the precursor versions. For some reason, I always think it was
@kcult (I don't know why) but the location was either Concord-ish or Rock Hill-ish. I can't remember for the life of me. Whomever it was was set up in his garage to do custom machining/milling. He had a tool chest full of barrels being worked on for customers. Did a great job on the very little "meat" available on the standard 10/22 barrel to thread it and get a flash hider on it. Charged me $40, I think.
EDIT: It was a user named K.Lee from Rock Hill (not KCult...too many "K" guys to keep track of!!!). He was just getting started with his own milling/machining/smithing company and cut me a huge break. Everyone was saying to expect $75-$125 for the threading. He did it for $40.
So after all that, I offer no help to you.