I matched the servo arm width to the Width of the Rudder horn. If you understand the Ackerman effect that isn't terribly important I could have gone with a shorter on the Servo arm. As I think I posted a picture I attached the tailwheel hook ups using a ball link on top of the arm. So far its been satisfactory. My tailwheel has too much throw and it I usually overcontrol on pavement although it hasn't been an issue on grass. I need to do some more fiddling with the main gear toe as it has lots of drag when pushing and pulling and i think this may contribute to the overcontrol. Ill work on that in the spring. I still need to fly a few more times this fall to burn up all my mixed gas.
As i recall I did the cuts for the rudder where I computed the would penetrate the side of the fuse, and i think I too noted that it was different from the instructions. This might be attributed to using a longer servo arm or they crossed the wires on run to the tail.
Sparky