By accurately marking the widest points of the cutouts (36 mm wide) and keeping the low edge of the alu guide more or less at a uniform distance from the hullside below the rails, it is not too difficult to get nice uniform cutouts.
Although mounting the outboard bracket on the aft panel of the cockpit seat as plans advice is probably the most sensible thing to do, I'm just not ready (yet?) to cut away a big part of the hull to make room for the outboard leg. Instead I'll mount the motor on the transom. The setup will be something like this.
