Here are photos showing the mod we did for storing our WD bars while camping and when it is in storage. My son did the work, but basically its a metal tube a little bigger than the curved end of the WD bar, welded to a metal plate that will fit on the A frame. My son drilled holes in the plate, then marked the A frame, drilled the holes, attached with bolts and then painted it.
When we are camping we secure the bars with a long lock through the chains on the end of the WD bars.