well id prefer my smith to do my barrel, he said he can do it as long as its standard thread pitch on the tenon, he doesnt have metric gears, but i think i found out its 24tpi
Unless they changed something with the A2 the threads have been 1 1/16 -16 since they started. I've done a lot of them for the original guns and the Gen II. I've swapped a lot of barrel extensions as well. The A1's are all Gen II. The only difference in the Gen I vs Gen II barrels is the extension. If he doesn't have drawings for the barrels it might be a problem as DT quit supplying drawings. He'll have to find them elsewhere.
Frank