Search for the Coca Cola sign on the vending machine. Vendo produces vending machines exclusively for Coca Cola, so if you have a vending machine with the Coca Cola sign on it you may have a Vendo Coke machine.
Check the silver colored coin slot. The coin slot must have the "The Vendo Company" words engraved on its surface.
Check the coin slot for the words "Deposit Dime or Two Nickels" and "Press Handle Down - Release". If you can see these instructions imprinted on the coin slot, you have a Vendo Coke machine.
Check the back of the vending machine. All Vendo vending machines have a serial number aluminum plate attached to the machines back above the refrigerator. If the number plate will contain the model number and serial number of the machine and the "The Vendo Company" words you have a Vendo Coke machine.
Check the color of the machine. Early Vendo coke machines were all red. Machines produced after 1955 were red with a white top.
Search for the words "Ice Cold" embossed at the bottom of your vending machine. If you can see "Ice Cold" written on the machine you have a Vendo Coke machine.