Started by locating the pilot holes for the upper bolt in the main gear support 10mm edge distance.
Square up the 6B11-3 and mark the part through the main gear support. Using a square, draw a line through the point on 6B11-3 and draw the cross line at 9.5mm edge distance. Also layed out the lower pilot hole. Drilled both holes in all parts. Now cleco the one hole, square it up with the upper longeron and clamp, now back drill the lower bolt hole.
Layout hole pattern in one 6B14-1 and transfer to all others. Cleco bottom, hold 6B14-1 in place and get 6B11-3 square, clamp both in place and back drill upper longeron and skin, cleco, back drill upright and cleco.
Removed 6B11-3's and layed out and drilled the 30mm rivet spacing, Re clecoed and back drilled the skins.