Coin Slot #29. Guide to the Mills Liberty Bell/Operator Bell
Including a guide to the Mills Special Gum Vender, No. A Liberty Bell, No. A Operator Bell, Automatic Gum Vender, Counter O.K. Vender, Floor O.K. Gum Vender and other Mills Bell machines with serials 100 through 32,000, as well as contemporary Watling, Burnham and Industry Novelty "Iron case" Bells and revamps.