Back in "The Day", many of us used Kraft radios, and KPS-14II servos. We used one servo for both ailerons, as well as one a piece for the rudder, and the elevators (both halves). These servos, which were "average" for the day, had 27 oz/inch torque, and a somewhat more fragile gear train than many of today's servos. I never experienced any servo related failures (due to the servos being underrated), nor was it an issue. Somehow we got by without today's super servos. I think that we can safely say that your choice of servos will be more than adequate, if not overkill for the application.

And overkill is O.K. Especially when it comes to a difficult to replace classic airframe.

-Robert

P.S. Like Dox says, go with the carbonite gears.