Betty Largent,  It's not clear if the tracker bars added by B.A.B. are
to be retained.  If absolute originality is required, then the B.A.B.
trackers should be removed and a keyframe installed.  This would also
require acquisition of a library of book music, and possibly
replacement of some pipes if any were removed by B.A.B..

MIDI can be added non-destructively to either the tracker bars or the
keyframe, and would seem to be a practical answer to the requirement
for continuous play as well as preserving whatever level of originality
you want.  Many of the arrangers for these instruments working today
will provide their arrangements in MIDI format, saving the expense of
having rolls cut or books punched.

I have a similar problem with my North Tonawanda organ.  It was
converted in 1929 to the Wurlitzer 150 duplex tracker system and in
the process several pipes removed.  Should I convert it back to the
North Tonawanda continuous roll system, for which music is virtually
unavailable, or stay with the 150 system for which a lot of music is
available?

To go back to the old system it would be necessary to get some new
pipes and to modify the Wurlitzer valve and pneumatic boards.  I have
elected to stay with the 150 system and add MIDI for convenience.

The MIDI addition is easily reversible.  I used Devtronix electronics,
Peterson valves and the Yamaha MIDI Data Filer (essentially a floppy
disk drive).  The Peterson valves are teed-in ahead of the Wurlitzer
valves.  Similar systems are being used by serious collectors these
days.

Fritz Gellerman