For sale:

This book was published by Supreme Magic Co., Bedford, Devon.  It does not contain a copyright date that I could find.  SIX CABARET VENT ACTS by Val Andrews contains six dialogues for vent use with "cheeky boy" character.  Contents: Go West, Young Man (vent and dummy in character as westerners); Lonely (the dummy is lonely and the vent soon learns why); Born In A Trunk (dummy relates his theatrical experiences); Not Well (the dummy is under the weather and the vent is a somewhat incompetent doctor); The Ventriloquist (ventriloquist lectures the dummy on the act of voice-illusion); and Caught Unawares (advice for those troubled with insomnia). 

This book is a vintage collectible, yes, but in reading through the comedy material, there are some very funny useful lines for today's entertainer as well.  eBay auction listing with photo of book:  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290638751386