Hey, did we loose some posts here or what? I was just reading up on this thread when the change happened.

Anyway, I'm with Ben here, with the addition that once you locate the axle for the surface, it should balance by weight at that pivot for dynamic resistance to flutter. Right near the AC of the surface(25% MAC) is where the pivot goes, maybe a couple percent forward.

I have done a flying-stab conversion along these lines to one of the Goldberg Mig-27 foam target drones. Of course, it's not a fast-mover - but std servos are plenty to control a 70 sq in tailplane on a 10 lb slow moving plane like this.