Karl, I'm excited for you and your disc project.  As for what songs
are not currently available, this is something I've given much thought
to over the years.  Can you imagine Simon and Garfunkle's "Bridge
Over Troubled Waters" played on a 27" Regina, or a 24-1/2" Polyphon?
I've heard it so many times, what can I do for a well arranged disc?
:-)

What would be a real interesting musical project, if permission were
sought, would be the ABBA numbers transcribed to musical box disc.
I remember many years ago reading of some professor of music likening
Björn and Benny's compositions to being up there with Mozart.

'What??'

Exactly, but after years of musing I couldn't agree more.  There are
some orchestral renditions on YouTube by the Royal Philharmonic, and
though welcome, they are rather 'timid' but are a taster of what the
music could be.  For example,

  http://www.youtube.com/watch?v=1Tknztyu9JI&feature=related 

Wishing you well with your project and looking forward to hearing of
any developments.  I could not agree more with what Nancy Fratti said
regarding the 27" size.  If you can get full, well-rounded arrangements
of new music on this size, I'll happily be your first customer.

Mark Singleton,
Lancashire, UK