Reader John van Kleef inquired about theatre organ books.  Curious, 
I hit www.amazon.com, which had no index for "theatre organs" but had 
a number for "Wurlitzer".  Here are several interesting ones:

Complete Identification Guide to the Wurlitzer Jukebox
  Rick Botts / Paperback / Published 1984
  Our Price: $20.00 (Special Order)

Mighty Wurlitzer
  Leaf, Carter / Audio CD / Published 1988
  Our Price: $15.98 (Special Order)

Behold the Mighty Wurlitzer : The History of the Theatre Pipe Organ
  John W. Landon / Hardcover / Published 1983
  Our Price: $55.00 (Special Order)
  Best of the Wurlitzer Organ
  Various / Audio CD / Published 1997
  Our Price: $5.98 + $1.85 special surcharge (Special Order)

  Reviews and Commentary for Behold the Mighty Wurlitzer : The History
  of the Theatre Pipe Organ

  Book Description : John W. Landon, himself a theatre pipe organist,
  has written the first history of the theatre pipe organ.  He traces
  its development from church organ to a theatrical instrument that took
  the place of a piano.  Landon also discusses the pipe organ's later
  emergence as a solo instrument, its use in radio broadcasting and
  phonograph records, and its present uses.  The book also includes a
  history of those companies that built theatre organs and biographical
  sketches of some of the leading theatre organists.  The appendixes
  list theatre organ installations around the world.

Steve McCollum