The photo shows the tiller pointing straight at the servo arm. This would require some sort of stretching connecting rod. Since the servo is mounted to the strut I didn't know if there wa a clearance problem with having the arm to the side. I'm assuming the photo is wrong and normally the arms do point to the side especially since you say you are using a dual-arm tiller.
I use a pull-pull connection from my rudder on my Stampe to the tail-wheel with the "connecting rods" being springs.