Started working on transferring the position of the longerons to the upper mounting surface. This was accomplished by careful measurement and verification with a tool I use in woodworking that gives me an accurate position of a hidden point on the upper surface. Once I was satisfied I moved that point to the angle brackets. Clamed down everything, measured the squareness of the HS to the fuselage (many times) then drilled first the right outboard hole then the left. This came out perfect to my great relief.
