New York, NY – Portland, ME – Mobile, AL – Knoxville, TN
(Yes, I know about Norcross, GA, but I don't have any keys made there.)
I'm a Francophile. Tom French, W1IMQ, has a Vintage Vibroplex site. He wrote and sells the Vibroplex Collector's Guide. At a minimum, you should check out his site. Get the book if you're serious about collecting Vibroplexes.
Serial Numbers per Year A graph of serial numbers used by year.