I applaud Bob Stewart's intention of adding a gas engine for power.
I love the unusual, and since it could potentially be authentically
matched it would be quite interesting.  Do any of the Wurlitzer
catalogs contain photos?

But I wonder if the make-and-break (hit-and-miss) engines mentioned
are constant enough in speed for this purpose?  It would not be
pleasant if the music sped up and slowed down as the engine did.

Are there alternative designs (perhaps throttling governor?) from
the same period of time?  I'm rather ignorant of engine finer points;
although I _always_ look at the engines on display at our county fair,
I've seldom stopped to ask intelligent questions about them.  Good
luck, Bob!

Todd Augsburger - Roller Organs
www.rollerorgans.com

 [ By 1929 constant speed gasoline engines were available, equipped
 [ with a fly-ball governor controlling a butterfly throttle vane
 [ within the carburetor.  Alternatively, a skilled mechanic could
 [ reduce the hysteresis of the hit-and-miss "all or nothing" speed
 [ governor for less speed variation.  Most applications are not too
 [ critical about speed; hit-and-miss engines are more appealing to
 [ onlookers!  -- Robbie