I cut and shaped a section of upper track to match the hole, riveted it in place, then match drilled the bulkead and fabricated a doubler plate with three # 6 nutplates. Alignment seems very good. One last nutplate to go along the side of the canopy sill and this part is ready for finish painting.
I would rather have to remove eight screws to take the canopy off than taxi around worrying that it may blow off by itself.
