1. Drilled the forward row of canopy holes (the ones that arch over the top) up to 1/8" diameter using a Plexiglas bit, then up to their final #30 size with a regular bit. Deburred the enlarged holes.
2. Decided that these holes could not be enlarged to 1/4" for floating rivets like the other canopy holes, since there will be no skirt at this location. Carefully countersunk the holes with a 120-degree cutter bit and smoothed them with a PermaGrit countersink bit.
3. Used a small Dremel ball bit to cut a small clearance pocket in the canopy for the upper canopy-handle screw. Smoothed it out with a grinding stone and a soldering iron.
4. Masked out the four areas of the canopy frame that will have to be scuffed for the later application of Sikaflex.
5. After deciding NOT to use the white rubber grommets I previously cut for the canopy holes, I cut new ones out a slightly stiffer, black rubber tubing. (This tubing, with a durometer rating of 70, is twice as stiff as the previous tubing, but it's still flexible enough to do the job, plus its black color will be better for this particular installation, since I won't have to hide it with caulk.)