I hope you didn't buy the machine that started this thread. In my opinion, it is overpriced by about 3x.
Here is another vending machine: A Schermack machine probably from the 1940s, although undated and no patent numbers on it.
Various exterior views:
Various interior views. The coin goes down the rectangular tube to the back of the machine where it acts as part of the mechanism allowing the knob on the front to be pulled fully forward by the customer and a stamp folder is dispensed, at which time the coin drops into a collection bin in the bottom of the machine.
The peanut-sized weight on the table goes on top of the stack of stamp folders to hold them down. The other one is on the near folder holder.