I leave the plastic coating on the wire. I don't like the crossed approach. If you make the geometry of the rudder servo horn match the geometry of the rudder's control horn, it works out perfectly. By "geometry", I mean the distance between the holes on the servo arm must match the distance between the holes on the control horns. And the "offset" of the servo arms needs to match the offset of the rudder horns. Offset at the rudder is the distance behind the hinge line that the horns are installed. If you can set it up with zero offset, this is easiest to understand.