This admittedly-muddy photo shows one way to drive an elevator linkage with tandem servos.
The servos are linked together with 4-40 hardware attached to the upper ends of
their respective output arms, and the elevator push-rod is attached to the rear
servo's (on the right) output arm on the bottom.
The bell crank visible below the front (left) servo is part of the pull-pull
rudder linkage.
