Brief Description: Replaced dual stick uprights on center spar
The dual stick uprights were originally secured by AN-3 bolts, but the new modification requires AN-4 bolts. This required enlarging the holes in the uprights and the front half of the center spar. I also drilled throuigh the flange on the top of the rear half into the seat top doubler, doubling the previous holes to achieve 20mm pitch.
