While the conversion of a book organ to play rolls would have been
justified twenty-five or thirty years ago, in this day and age I just
don't see it.  An off-the-shelf MIDI conversion (a Pell Harmonist,
for example) would have the done the same thing without drastically
altering the organ.

One of the reasons, I believe, you don't see many Gebruder Bruder
Model 107s today is that they did not lend themselves to conversion.
The scale doesn't come close to any domestic band organ scale.

Before WW1 they were very popular with Wm. H. Dentzel and W. F. Mangels
for use on their carousels.  It is my belief that, after the introduction
of the Wurlitzer Style 153, most of these Gebruder Bruder organs were
traded in.  This was encouraged not only by Wurlitzer, but by the
carousel builders themselves, who often acted as agents for Wurlitzer.

Bruce R. Pier