Continuing on with the right rear canopy skirt, I drilled the final holes (for rivetting the rear skirt to the side skirt) with the canopy at my workbench. This enabled me to pull the skirt pieces in "to the extreme" in an effort to get a tight fit all round against the fueslage.
In the end I'm reasonably happy. The skirt fits very well against the fuelage top, but not so well along the sides, at the bottom edge of the canopy. It's not really noticeable without running your fingers along and feeling, but I am a little concerned that it may create a draught in flight. If it does then I'll just work on something to help seal it up....or work out a way to "bend" the side skirt inward a bit.