DW, too much stuff there. It's just a simple freeslot thingitem in SOCedit that has a corresponding freeslot state. The thingitem itself tells some general stuff about the scenery item; stuff like nogravity and scenery. The state says some stuff like which sprite to use, and stuff.
Of course, if you haven't figured out, this requires Socing. While no, it's not too hard, it's still Socing.