Underside. How is it wires? How does it function when playing? Lamps also.

I would guess the shoot again lamp energizes the gate coil? But it would not reset until you drained hitting out-hole switch. So you keep it until draining from lair or SDTM.

Why two lamps? Red / Green do what while playing? Checking wiring and playing with glass off would answer what it does. Looks like a well done modification. Underside would tell a lot.

I don't think this is going to be a prototype if that is what you are thinking. Those inserts are done well but not standard looking. Also the lettering on the cliff. Well done but not period.