OK, I know it’s not O gauge, but it’s still pretty cool!
I think it could be N scale. No information was given on the website. You probably could do one in O gauge, though. I think that this is a fantastic idea and it would be sure to attract people!
Plus, I also know what the perfect thing to sell in this vending machine would be. Once, when I was a kid, my family went to Minot, North Dakota. At a K-Mart, there was a vending machine that actually sold little toy trains! For 25 cents, you could get a steam engine, tender, Alco FA diesel, tank car, reefer, caboose, streamlined passenger car or dome/observation car. They actually had rolling wheels and couplings. Each was available in four colours: red, blue, dark grey or light grey. Needless to say, I used up all of my parents quarters on that trip. I still have my collection of these little trains. Unfortunately, I have never seen another one of these vending machines since then!