Before drilling the left two forward fuselage ribs (on the bottom right in this picture), I used some scrap 1/4" bar stock to correctly position the canopy frame between the right two ribs.

It seems simple, but drilling these two left ribs took a good half day of work. Their vertical position will very directly affect the fit of the forward fuselage skin to the canopy skin. If the vertical position is off, even just a little bit, it will result in an unsightly step at this joint. Since the fit of this joint is the whole reason for making these custom parts, I very much want to get it right. With all four of the ribs drilled and clecoed in place, I was able to remove the plywood subpanel and center spacer rib.