I used Gumballs.com when I was running machines years ago.

https://www.gumballs.com/

It depends on the size of the wheel. Once they are open it is easy to see how they work. When you turn the handle a wheels underneath the gumballs spins around to get one of the openings on the wheel to line up with the chute. It all depends on how big the wheel openings are. Some are adjustable but that old it is probably a fixed size. Obviously you can only use a gumball that fits through the openings. If you use smaller gumballs or even candy like M & Ms it will dispense two gumballs or multiple candies. Wheels can be changed.