Thanks - this is most helpful info.
When I get home - with the fuse sitting upside down in a cradle, I'm going to plug in the flight battery, turn it over and set it on the basement floor, switch the Tx on and then the airplane without disturbing it or hooking up the ailerons and see what happens.
If the rudder still shows deflection, I'll rebind to the airplane and if the rudder still isn't faired, reposition the output arm on the servo for true center, make adjustments on the clevises to achieve rudder/nose gear neutral, then leave the system on for a while. If it drifts, I'll know I still have a problem.
Telling all these details just in case there may be an "Aha!" moment and a "Here's what you're doin' wrong or shouldn't do..."