How about using the moving platform system? It would be like setting it up like a platform elevator, but have the start floor and eld floor be in the same place, just turned 180deg. That should make it turn translationally, and you can adjust the speed in the Moving platofrm anchor marker script. You could make it havve a third "floor" that's rotated 180 from that. I don't know how to make it go back to the first "floor" position using the same "up" button, but you could have two buttons, set as "up" and "down" (back and forth) buttons. You could use translational markers set at 45deg in case it's turning the wrong way back and forth (there might be rotation direction parameters in the platform or rotation marker scripts, I dunno)
There's a video on how to do this: