I bought a postcard in an eBay auction this morning that includes the
following text on the reverse:

  "The old 'magic' barrel organ was manufactured in London about 1737.
   No one knows how it came to the mission.  While its gay tunes were
   unsuited for mission use, doubtless its music charmed the Indians,
   and at one time is said to have saved the mission from an attack by
   the fierce Tulares."

You can see the pictures here:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1081829607

There is an excellent web page with more information on this instrument
at  http://www.standingstones.com/sanjuan.html

John Haskey