Went ahead in chapter 12 and saw there were some gussets that needed to be made for this area later on. Since I couldn't see a good reason not to make them now, I went ahead and did so. The intent, based on Ron's recommendations, is to leave it all clecoed until the fairing box install. The Manual does a good job of explaining the rough shape and realtive size of this piece, but I was carefult to measure on the plane precisely how long and wide the piece needed to be to capture the requisite 3 rivet holes on both top and side edges. After "practicing" on 3 pieces, I had two useable ones.