The mounting rail pin on the cot has rubbed a gash into the wall of the slide out.
The solution is to use heavy duty rubber matting fixed to the wall about 12" tall and 88" long to provide rub protection for the entire wall section that comes in contact with the stored cot. The rubber has been glued with contact cement and then attached with self-tapping screws to ensure it will not fall off.
The forward stretcher was rubbing a hole through the metal wall below the left from the counter where we store Lucina for transport. We installed a rubber mat vertically on the wall which appears to be working as desired.