After working several hours cutting up the tail fairing to make it fit properly, I decided that I would get better results by laying up a new fairing in place. Since the fairing will wrap under the leading edge of the horizontal stabilizer, the lower H.S. fairing needed to be installed first.
The right fairing geometry was tweaked slightly, then a strap duplicator was used to drill rivet holes in the fairing aligned with the existing holes in the fuselage, then clecoed in place.