When I got it out of the yard all that was left of the tower were steps going up the side of the cab and some of the control extensions (throttle and steering).  I don't know how they had the shifter set up (if at all) but there was a way to start and stop the truck from the top, as well as steer, brake and accelerate.  I'll post pics of it as it was when I got it, as soon as I get back to Cali.