Hi Bill,
The lugs are ultimately bolted in, so #40 holes and clecoes can hold them in for test fitting. It's easiest if the canopy is not yet fastened to the frame. Use a spacer to allow a small gap (1/16-1/8") between the frame and the longeron. Using any thing to clamp or hold the lugs temporarily (tape works) to the frame and get them aligned as close as possible to going through the holes in the F-757 gussets and engaging the latches. Mark and drill them so you can hold them with clecoes, then test the latches. If the fit is not quite right, redrill to #30, adjusting the hole for a better fit. and retest with # 30 clecoes. When satisfied, drill out for the bolts.
Hope this helps,
Roberta