Old single barrel shotguns can be had so cheaply that I can’t see the need to make one.
Around a year ago, I bought one for $40 plus tax. It was fairly rusty and the for end was loose but the bore and action were fine. After tightening the fore end, which was a little harder than I thought, and cleaning off the rust, it looked like a perfectly good user.
Lock-up is tight and it even has an ejector. I have only fired a box of shells through it but it shoots better than most more expensive guns and the action is perfect. It also has a hammer.
Was this in California?