After testing the 30 minute epoxie, set time and full cure strength, the blades and pins were glued into place. Note that photo in manual has anti-rotation pin perpindicular to fin base. I put my pins in on the same angle as the plate and hook of the fin. Glue grooves were cut into the plywood plates both sides for added strength. Also I made up some 3/8 x 3/8 x 1/8 plywood squares & with medium Cya doubled the up the pads for the hatch mounting screws, needed no, but my personal choice.

Photo 1: The red crosshatching approximates what I did with the dremel and a 1/8" carbide ball nose burr.

Photo 2: Large red arrow shows the direction of the fin movement as it is being assembled. Red boxes to highlight changed from instructions.

Photo 3: Fins mounted but no glued yet all fitting will be done before gluing of final assembly.