You need some foam as is used in engine boxes to hold the motor. Cut a piece about 2" deep x 1" thick and length about 1 1/2 times the width of your fuz about half way between the MK unit and your elevator servo. Punch a hole through the middle of it using a piece of sharpened brass tube a bit smaller than the dia. of your carbon pushrod. Stick a piece of double sided tape on each end of the foam block and cover them with pieces of covering film backing so that when you thread the block over the pushrod the ends dont stick to the insides of the fuz until you get it in place. Push the block down the fuz and fit the horn and arm onto the elevator servo with the elevators centred so that the block lies in the correct position in the fuz. Now reach down and being careful not to move the foam pull out the film backing pieces and the double sided tape will grab the fuz sides. The pushrod will move back and forth bending the foam block which will provide damping to stop the rod resonating but still allow very free movement. This has worked perfectly for me in my last to models.

Regards

Malcolm