My friend is ripping a couple starboard shims that will sit inside the two raised parts on the lid. He is then going to bond it to a piece of starboard the size ( I think ) of the lid. The end result will be. Removable cutting board that should lock in place on top of the lid.
When done I can post a picture but he plan is the same, space for a couple guys to be cutting at once on either end of the box.