Steve, looking at your pull-pull set up I would think it would help if your made the servo horn match the 1 O'clock 5 O'clock configuration that you have in the tail. It should give you less binding as the servo moves through the travel.

For those interested in a Dave Platt spinner, all I did was give Dave a call on the phone using the number posted on his website. He sent me a spinner right out. Be prepared to do some work making a special spinner nut and a spacer for the backplate which has a hole that is almost 1/2" in diameter.