I have the balls for my Rocket, but I had to straighten the control arms to give me more room for my left thigh.
This moved the throttle ball too far outboard for my comfort, so I replaced it with... get this... a long 3/8 socket from my socket set. It captures an AN365 nut perfectly (of course) and the 1/4" square drive is ideal to pass the AN3 bolt through it.
No pic yet, but the shaft extends out over top the prop/mixture controls and is more conveniently placed for comfortable operation. If I put some heat shrink on it, it will disguise the fact that it came from my toolbox.
In conclusion, two balls and a shaft extension make for comfortable single-handed control.
V