Having trouble finding an unobtainium extractor for an old gun I was contemplating having one cut out of .150 steel. This is about an inch and a half long and maybe a 1/4 inch wide. Question is do you get a lot of warp with a plasma cutter and how accurate/smooth is the cut?
A file and some bar stock is your friend. Perhaps some heat treating afterward. Rarely is a lot of money needed. Just patience. Gunsmiths are paid for their patience. Not their technology.
There would be zero to minimal warp. The problem is finding someone with a CNC plasma cutter that would be willing to do it reasonable. If your speed is correct, it's almost smooth as butter. Doing it by hand would be a real trick.
Between OnlineMetals' huge selection of tool and mild steels in almost any dimension, and perhaps a drill press, I think it could be done fairly easily.