I have bought a Nijdam foldable sledge, but when in its folded state, it has 4 screws and 2 wooden boards that do not fit on the sledge itself. I designed a very simple solution to hang those parts on the side of the folded sledge.

You need to print 2 of these per board for a total of 4 pieces.

Insert one of the top pins in the bottom hole, then screw the screw in the top hole, holding the board against the hook. Repeat for the other top pin, and hang the hooks on the side of the sledge.

This might work for other brands of foldable sledge, but I only own and tested this one.