James – we have a Dufour 455GL and the rotary drive is attached to the Starboard wheel. Access to the motor is through the starboard cockpit locker. At first sight it seems impossible but the panel inside the locker adjacent to the wheel can be removed if you cut the sealant around the edges. You will then have full access to the rotary motor and drive chain. Hope this helps.
The membership association for owners of Dufour Yachts