My friend Peter Dzubay adopted a cool novelty dummy at the 2017 convention...a ukulele! Mr. Berger bought at least three of these from L. Davenport & Co., a London company that manufactured and sold magical apparatus, novelties, tricks, and some vent dummies. Mr. Berger's relationship with Davenport began in 1932 and continued steadily until 1971. He ordered dozens of dummies, as well as pocket figures, Toby Jugs, parrots, and ukuleles. Throughout the 1940's and 50's, Mr. Berger purchased dummies and heads for resale to vents across the U.S.
Mr. Berger ordered his first ukulele on February 25, 1957. It was listed in the Davenport catalog as, "Ukulele changes to Vent". He paid the equivalent of about $12 for it (about $107 in 2018 dollars). He was very impressed with the piece and responded to the company, "I would like to introduce this novelty at the Houston, Texas IBM-IBV Convention next June," and ordered two more.
Mr. Berger didn't record much information about this piece; I don't know if this is one of the three for which a purchase record exists or if it was acquired at some other time.