Brief Description: Left Elev: ribs for elevator trim slot
Here's the rib I constructed from 0.03 alclad scrap. This will fill the space nice while still allowing water to drain. That's the original skin, and the better looking side (the other side is a real mess....trust me).
A lot of other builders recommended this approach on Vansairforce.net, and I actually enjoyed constructing the piece from a template. The skin trailing edges diverge forward at a 15 degree angle. I traced two lines diverging 15 degrees from a point, plotted out where to start/stop the part so it'll fit in the space behind the trim tab spar and the skin trailing edge. It fits well.