I have completed the install of a 36 volt Rhodan with an 84" shaft on my 2520 XL SC and would be glad to text pictures to someone who can post them. It is mounted on the port bow about even with the windlass and folds down to storage position across the deck in front of the forward berth. I cut about 4" out of the railing just forward of the rail support that is even with the rear of the windlass and was able to slide a 9" stainless steel rail tube with an ID of 1.26" over the rail forward of the cut. This is then slid back across the opening and against the vertical post behind the cut to close the opening. Works great!
The three group 31 AGM batteries are located in front of the anchor well access hatch door at the front of the forward berth and the motor plug is installed on the hatch door. The wire from the motor is fed to the plug thru the small hole in the anchor deck hatch. The motor unit had to be shimmed to level it and the nuts and washers were installed by reaching thru the deck hatch door and the forward berth hatch door.....not an easy task.
Note: After making the railing cut, the railing forward of the cut moved outward about 2" due to the tension in the railing. This allowed the 9" rail piece to be slid on. Closing the opening by sliding the rail piece to the rear requires pulling the railing back into alignment . Tension holds the sliding rail piece in place.
Phil