John, the boards on the outside are/were not grooved, but the sheet metal angles are level with the skids, because they sit slightly above the board the same as the 'humps' on the skid strips, so cargo doesn't slide on the wood .... from any original wood I've seen it always has been 3/4" - and I'd expect MarK to be selling 7/8" bed wood rabbeted for the edge angle if that's what was original [their oak is actually 25/32", not sure about the pine]
Bill
