Seems someone posted a pic on here no longer than 18 months ago that showed 2x lumber mounted on edge to guide the camper and place it fairly exactly. It must have been back braced to the bed walls. The 2x was angled so that the camper would "find it" when descending and could be placed fairly snug between the "guides". It was forward of the fender wells and I don't remember if it extended between the fender wells. I guess if you had room between the fender wells you could..i.e. if the camper tub was 44" wide you could extend the 2x to there, and as far back as the camper wings started.
edit add...The top of the 2x could have been cut at an angle length wise. That would give more vertical support as opposed to the entire 2x being at an angle. I suppose covering the load side of the 2x with carpet would prevent scuffing the tub.
May be I dreamed this. It would be a neat experiment though.
