The ladder hooks are wall-mount, so they just have a threaded shaft. I didn't figure the drywall could hold that much by itself, so I added this.
It's just some dimensional oak from the Orange Store. I cut one square for each hook and routed the edges. The squares are rounded over on all four front edges. The tall rail is only routed between the squares.
Then I glued the squares in place and drilled holes for attaching the rail to the wall. The holes are counter-sunk so the screws sit below the surface of the rail.
Now Danger has a place to keep army men, airplanes, or Lego bricks.