Use a upside down Tube Union as a POU
Louver.
Use a drawer slides commonly found at
hardware store with a tub to create a drawer
Stackable shelf units.
Simply reverse the based mounts to complete the Z shape.
Use a universal joint (or two) with nylon
washers to create a pivot arm.
Let me know if you want direction on this one.
Only additional part needed is a clevis pin.