Assembled the aileron bell crank. The dimension for the spacers on each side of this were more of a starting point than a finished size. Did a lot of trial fitting and taking off a few thousandths at a time by chucking the spacers up in a drill press and sanding the end on some 100 grit sandpaper. very time consuming, but in the end they came out perfectly. The gussets you can see in the pix below seem simple enough, but the challenge is that there's enough flex in the bulkhead tabs that it would be easy to adjust them far enough fore/aft that the holes in the bulkheads wouldn't line up with the upper skins. My fix for this was to cleco the upper skins in place and then clamp these with some vice grip clamps, then uncleco the skins enough to get in there with a 90* drill motor and match drill.