Began installing the rudder fairing. The fairing adds some aerodynamic form to the otherwise flat-faces rudder and comes as a pre-rolled sheet of aluminum that's reasonably close to final size. The trick to installing it is to align it close to the back edge of the fuselage while still leaving room for full rudder rotation all while avoiding interference with the other surfaces in the tail area. Luckily, when I built the rudder back in 2013, Jon Croke's Homebuilt Help video provided the tip to not rivet the section of the rudder where the fairing installs. That turned out to be very helpful today.
To fit the fairing, I trimmed the "bottom" corners (the piece is symmetrical so the bottom is arbitrary) so it would slide underneath the already installed rudder trailing edge skin where it seemed to stay in place with friction pretty well. I then reinstalled the rudder and kept readjusting the fairing until its clearances were all good with the surrounding aircraft sections. I marked the skin with a Sharpie to save its position, uninstalled the rudder, then drilled out a rivet line in the fairing using the aforementioned rudder trailing edge skin to match drill.
All that's left to do is to trim the fairing edges. They are just right at the top (~10mm beyond the rivet hole), but at the bottom there is excess skin (~40mm) which I will trim before riveted it on top of the rudder trailing edge skin.
Test fit with only a couple of holes drilled into the rudder fairing.
Same view of the test fit, but from slightly behind.
A quick look at the fit with elevator reinstalled to confirm there's still no interference.