The only reason I used the drill press and the new high speed center cutting mills is that I had a drill press already. That was simply a time saving device that allowed me to plunge cut the holes you see. The cross-slide vise allowed me to remove layers of wood at precisely the same depth, in different areas. None of it was totally necessary to build the gun, and as you point out it could have been done with hand tools alone. It's been done many thousands of times that way, and continues to be done that way by some today.
My gun-building mentor at the time was very impressed with my effort and pointed out that he'd never seen anyone leave that little "arrowhead shaped piece of wood" inside the sear leaf spring. I replied that I left it just because I could.
