After the first side is completed, the process is duplicated for the second. The table is the reconfigured to build the box. The fuse is built upside down, on the top longerons, because they are flat. The trick is to keep the sides straight and plumb while the intercostals are fit and tacked in place. That's where the fuse jig comes in. Once it is assembled, and the sides squared up, it becomes another exercise in cutting and fitting. All the tubes can be put in place up to the break in the fuselage by the pilots shoulders. At that point the tail post needs to be installed.
Using the tailpost jig, the tailpost is located and the upper and lower longerons are fitted to it. It is important to leave room atthe top logerons for the elevator push rod. A lot of builders didn't leave enough room there for a rod end, so the plans show a fix, but it's not pretty.
After the longerons are tacked to the tail post the remaining intercostals can be added. There are a couple of long diagonals that are pretty tricky. I did some head scratching to figure out how to mark the angles for cutting, and threw away a few pieces of tubing as well.
Once all the tubes are tacked into place it's time for final welding. I made up a fuselage rotisserie out of pipe and some fittings, but even with that the truss gets pretty unweildy. All joints need to be cleaned well to remove all traces of rust and oil to ensure good welds. A good wire brushing and a wipe down with MEK (use gloves, proper ventilation and discard the rags properly) It is important to weld the joints in the proper order. Each joint should be welded in a specific pattern, usually done in opposing quarters, to minimize distortion. The order the joints are welded is important as well. I started at the front and worked back, never welding both ends of a tube at the same time. My philosophy is to slowly bring heat in, getting the whole joint warm, and retreating the heat slowly. (I won't get into post heat treating arguements, but I only did it when I had to correct a distrortion.)