I was an apprentice at BAC Hurn when they were building the replica Vimy & parts were made in the Training Centre. The fuselage structure is the same node repeated with differing tubes between - locked in by bracing wires that also have welded pick up points on the node. Very simple to produce but it took a skilled welder (NOT one of us apprenti) to do the job without messing it up. For any monocoque aircraft the problem would probably be finding someone with the skill to hand roll the skins and the patience to produce all the cleats & ribs.