Install additional top rivet in side skin join

In all layers except the outer skin holes are present in the various layers. They do not match up so well however. The outer (front) skin layer omits this hole, and it seems that Sling do not place a rivet at this location. The effect of this is that a gap opens up between the front side skin and the rear side skin in this region owing to the side rail structure flexing out the front side skin.

I decided to place a rivet at this location and chose a 4.8mm rivet since all the rivets - in my build - along this line are also 4.8mm. This larger rivet size also allows the mismatches to be absorbed almost completely. As noted in a previous post, the inner layer (in a Z-bracket) has been folded about 1mm out of position creating a gap that a rivet would need to pull together. To avoid distortions, a AN3 thin washer was glued in place. Subsequently these washers broke away. The limited access now made it impossible to reinsert the washer. Instead I made a washer-like insert with a tab so that a pair of locking tweezer could manoeuvre that insert into place under the Z-bracket tab.