RE: Picked up used H9 Taylorcraft w/G26 have questions
If I recall, a 5/32 wire nose gear arm fits the shaft quite well. I prefer plastic linkage to the throttle using a short threaded section to the throttle arm on a gasser for the reason of avoiding carrying RF noise back to the receiver or near the antenna.
The idea behind slight up trim to the ailerons is to simulate wing washout and reduce the stall tendency at the wing tip. With washout not wanted at full speed or while inverted, the simulated washout at lower throttle settings seems to be working well. I should add that on the Cub at the same time as the up mix was programmed, which required setting the plane up as flapperon type, the door was open to also set a generous amount of differential to reduce some yaw effect away from the turn. The idea there of course is to reduce the the outboard (to the turn) wing drag caused by a down aileron. Between those two changes in setup, the nasty habits of that Cub were controlled. There is also on that Cub some rudder mix with ailerons but this was done from the start knowing that Cubs liked it.