I clecod the leading edge together and then to the main spar. I inserted the inboard rib (which isn't pre-punched) and marked the location of the holes. Then I removed it and fluted it to make it flat.
I then made the leading edge to tank joint plate by marking a line and bending some 032. The second picture above is of me trying to bend this stuff. I re-inserted the inside rib and then pound the joint plate (OK, tapped) until the line was visible in the skin's holes. I was really careful with the tapping and coaxing the rib and plate into position. Then I started drilling and inserting clecos in a linear fashion. It turned out perfect.