Mechanical Memories Magazine

The Threes machine pays out a packet of Polos as a reward, there is also bell that rings
to signal a payout when you manage to get a winning combination of playing card
symbols on the head box display. Although the machine only has one ball bearing, a
very cleaver mechanical star shaped wheel lets you fire the ball three times for one old
penny, so you have even more chances of getting a winning combination.
Internal view of the head box,
showing at the top nine relays associated with each of the nine card symbols.
Page 12