wmoses wrote:
Just had a look at mine. Built for an RVQ and a small shelf, so it should be pretty sturdy and it is. It is 3 ft long with seven screws placed at equal distances apart and about 3-1/2" from each end. Looks like silicone adhesive is between the rail and fiberglass side wall. Doubt if any more than one of these screws hits any stud, which in my RV would likely be aluminum.
Pretty good chance since your trailer was factory "equipped" with a RVQ "mount" the manufacturer placed some reinforcement BEHIND the area where the mount was to be placed.
I would doubt that they screwed into the skin only without something else. Skins are rather thin and would need something like thicker metal, wood or something like hollow wall anchors to spread the weight out..