I went back out and fit the fiberglass to the rudder and the cutout in front actually fits pretty nice. I had to clean up the edges a bit since the scribe line was not equal on each side and the front area had a distinct slant, but once trimmed significantly and fitted to my rudder it looks a bit better.
Lets change this plan gotcha to:
"be weary of the scribe lines symmetry and ensure you cut short before trimming to the specific fit of your rudder. Figure 2 does not match the scribe line on the R-911 Rudder fairing."
I'll add some Flox to fill the gap in front of the rudder horn once the temperatures here warm up a bit.