It helps that I have a pretty good understanding of diesel powered vehicles, wiring and electronics in general, and I went to the trouble to trace down *BOTH* ends of every wire, prior to removing it. Only those that I was *ABSOLUTELY* sure weren't essential to anything were removed (the removed recording box and cameras, the removed stop sign, the removed 2-way radio and antenna, etc.) The front stop arm was air powered so I didn't have to worry about wires there ...
The air lines are conveniently in the control panel, the supply feeds a pair of solenoids which open when the 8-way lights are on (wires were cut by the school district prior to my picking up the bus). Since the 8-way lights won't be retained, I can re-purpose the air line for an air horn. I kept the hose, so I have everything I need for installation.