Earlier today I was reassembling a pressboard shelf system, and I saw these shelf connectors. One piece screws into the side of the cabinet, and the other piece is inserted into a hole in the shelf. The shelf then drops over four of these, and the dovetail shape keep the sides of the shelf from bowing out. Obviously real wood workers wouldn't use such a thing, but they could have some use for MDF shelving. Has anyone ever seen these offered for sale anywhere? Plus, I need two of them to repair this shelf system.