We tested the locker and it works grreat! It runs on 70 lbs pressure. Here are the (crappy) pics of the final install. The air valve is at the top of the pic with The input line going down to the tank, output line going left to the locker air cylinder, and a small brass vent(that air escapes from when
unlocked). The tank goes thru the regulator up to the air valve, with a quick connect for air tools. The switch is the one on the right (not labled) and the red light goes on only when locked. When I have time, I will have a machine shop build the shaft for me and build this same unit with a 1 1/16" bore cylinder instead of a 3/4" bore air cylinder. The larger bore cylinder has a larger return spring and takes less pressure to operate.

L.B.