Just for the records, welding, or even silver soldering, on a patent breech, can cause unforeseen problems. I brazed a sloppy hooked breech up some years ago, and found it was made from some exotic steel alloy, that air hardened to the point that I couldn't drill the hole for the tang screw, even with a cobalt bit. I annealed it, and even then, it was very hard. So I trashed it and bought a fixed plug to replace it.
Hungry Horse