License Tag in Miniature Identifies Auto Keys (Oct, 1939)
I think this is a great idea. Though I’m sure that Bruce Schneier could explain to me why this is a bad idea, I’d still love to have one. I can never remember my license plate number! Here is an awesome gallery of similar key chains.
This guy sells them, but they don’t look nearly as nice.
License Tag in Miniature Identifies Auto Keys
A metal tag stamped out as a miniature reproduction of your automobile license plates is attached by a chain to a novel key ring designed to hold car keys. Tiny copies of any individual license plate of any state may be obtained. The identifying tags are especially useful where a number of sets of keys to different cars are kept in one place, as in a public garage.