Since I elected to install the tail tip NOT per the plans, I had to do some extra surgery on the tail tip. If I left the tip the way it came, and only cut out the rear section of the fiberglass tip, then the length of the tail tip is too long and it sticks past the end of the rudder (see pictures on next page).
To prevent that I cut off the same 3/4" of tail tip that would normally be burried beneath the skin of the vertical tail. That made the leading edge of the fiberglass align with the leading edge of the vertical tail, and made the trailing edge of the fiberglass align with the trailing edge of the rudder.
Using the after-I-already-cut-the-thing pictures you can see how with the original bottom edge of the fiberglass tip aligned with the leading edge of the tail (photos #1 & #2), that the trailing edge sticks out beyond the trailing edge of the rudder (photos #2 & #3).
The original base of the tail tip installed to show what WOULD have happened w/o surgery.