-After a phone call to the friendly Van's help line yesterday, I learned what the problem was. I had already test fit the right vertical bar and if fit just fine. They knew precisely what the issue was. Apparently a few kits had gone out the door with certain vertical bars that were drilled in a slightly misaligned jig. The fix was to grind one end of the vertical bar until it fit (will post a pic later). It was not an easy to thing to take a beautiful chunk of anodized aluminum to the grinder, but they assured me it would be fine. After doing so, if fit perfectly, so I primed the ground end and pressed on.
-Riveted on the right bulkhead
-Riveted on the seat ramp supports and floor support angles (see pic below)
-Riveted both of the vertical bars onto the spar
Aft center section spar completed. Vertical bars are on the other side.
