Here are some photos from inside also. I will remove the screws on the panel in the berth aft to get to the back of the motor bolts. It is interesting that it does not have any nuts there? Should I add nuts, do I need washers, should I have any backing or just tighten the nut onto my new bolt. With 4200 to seal it up? The current board is 16 x 6 x 2.