Back then hot dogs and hamburgers were called sandwiches. My parents and a lot of older people around here still call them "Hamburger Sandwiches."

I think the machine itself is on the level. The seller, however, I can't vouch for. They obviously read the ARF thread and copied some of the info. Or, maybe one of the posters is connected to the seller?

I couldn't find any info on that particular machine, or the companies listed. But, I did find info on some other radio hot dog cookers from just after WWII.

Here's a link to an article on a vending machine one: http://books.google.com/books?id=vuE...%20dog&f=false

GE made the machines for the Automatic Canteen Co. according to this article:
http://books.google.com/books?id=cxg...0radio&f=false

I also found another company called Radio Chef trying the same thing. The name of their device just may be the greatest name of all time! It was called the Speedy Weeny: http://books.google.com/books?id=KRo...%20dog&f=false

The device in the ebay ad looks like it's pre-war, probably early 30's. Since others were trying the same concept, I would say this one is legit too. However, the story of the government confiscating them seems a little far fetched and maybe concocted to make it seem more rare.