Glad to know it wasn't something obvious. I asked because I plan to use one of my trailers as my "command tent" for a Scout camp out weekend in a week. I want to start loading stuff up now while I have time and don't want snakes or other critters getting into the trailer through the holes. Duct tape was my solution. However, I figured to check for some kind of cool erector set double floor kit of something first.
By the way. A standard military cot will almost fit sideways in the bed of a M105. If you pull the side boards off, put the cot across the front of the trailer with the ends of the cot on top off the bed rails, it will not stick out past the edge of the rails. Then put the side boards back on, top on and you have a cot secured in the trailer, lots of room underneath the raised cot and a pretty good sized "living room" left over.