Coin-O-Matic © 1957 Australian Engineers & Metal Stampers.
4-reel bell.
The Coin-O-Matic was made by a man with the surname of Wilson, in his garage at Five Dock in Sydney NSW Australia. He only made about 10 machines a year, maybe less, so they are very rare.
The particular machine was produced in 1966 and was installed in the Entrance Bowling club, which was one of a few clubs Wilson in his sixties at the time serviced. This machine didn't utilize a clock to determine the reel speed unlike all the others of it's time. It used a hydraulic damper instead, and the viscosity/thickness of the oil/fluid adjusted the speed, and this machine is one of a kind!
Loose Change Blue Book for Slot Machines [4th Edition]