The remaining holes in the bottom skin were drilled to final size and cleco'd. The rivets shown in "Detail D" were drilled and cleco'd. The holes shown in "Detail S" were drilled to final size, 3/16". The bottom skin was then removed to gain better access. Due to recommendations from other builders, the rivets holding the bottom of the Cross Tie Box assembly were drilled out and replaced with cleco's. This was done to gain access to areas while building.