Dead easy. Connect one arm to stab. as usual. Then connect the second servo output arm using a rod and two clevises. to the first servo arm using holes in the arm which are in the same positions on both output arms.

As two servos will rarely give identical travels with the same receiver signal I very slightly enlarged the holes in the output arms where the two servos are connected to allow a little slop so the servos aren't fighting each other

With two JR8411s the F4 stab. has a mass of power making life easy for the servos, further reducing risk of failure. .

A JR matchbox could also be used. If one servo fails there every chance I will retain elevator control. Control redundancy, gives me a comfortable feeling !
BRG, David Gladwin.