Interesting item, I think I know how to those were made - will experiment and if successful will offer for sale...

John :-#)#
www.flippers.com

OK, I spent a few minutes playing with one of the reed switches you pick up for doing simple alarm systems. Attaching the reed switch wires to my meter - open circuit as expected. Now put a small magnet on the reed switch so it just about trips, then move a steel pinball near - this will trip the reed switch in some cases, enough that my expectation is they simply used a second magnet to set the reed switch up so it was extremely sensitive to metal objects such as a pinball, causing it to trip.

Now if the original was a normally closed and the ball opened the reed switch that only means they either used a normally closed reed switch and a magnet to preset it, or they used a normally open reed switch and the magnet tripped the switch in such a manner that the ball would detrip it (less likely).

Play around with some reed switches, get the really tiny ones and some of the super magnets - tiny button ones are probably best.

I'm too busy now with some restorations (Maneater video for one) to do any more at this time.

John :-#)#
www.flippers.com