Pictures and information courtesy of F. Long

As you can see from the photos it's a Wurly 16 play mech. The very cool thing though is that this machine stores credits. It will not play the next selection unless you depress the button above the coin slot.

The red light on the selector panel denotes that there is a credit while the neon depicts the selection chosen. The selections are made by the rotating knob on the front of the cabinet. Very neat and way ahead of the Musicolas which were produced at the same time.

Video featuring the Melody Master by Frong Long: http://youtu.be/3eNGfunAlMo