Bob,
All of the spacers ARE welded into place, except for the one at the muzzle. However, I do a lot of measuring and layout work, before I machine those spacers, calculated to give me about .002" /.003" of convergence, in the last 6 inches. That is easy to regulate with the tapered wedge between the muzzles, at least it has been so far. I hope that I don't end up eating those words on this build. I'm just heading down to my shop to do the final carding on all of the reamaining small parts,ie: safety slide, firing pin bushings, screws, etc. Tomorrow morning I'm starting to blue the action.