After speaking with Tom Grace,  the craftsman restoring the Disneyland
Collection, I learned two things:

1)  The encoder is kept on during the service hours of an instrument
    with a MIDI player-  the "shutoff" included in a tune file at the
    end will operate a motor (and additional lamp circuit) shut-off and
    thus turn off the pump and blower.  When a coin is dropped or
    button pushed,  the pointer which evidently resides in the
    encoder's memory,  "points" to the next file, which it plays,  and
    so on.

    This reminds me of pianos and organs which had a constant "hot"
    wallbox circuit,  and often had a separate lamp in or on the
    machine to indicate it was ready to accept nickels.  Mystery solved
    thanks to Mr. Grace.

2)  The fabled Disneyland Welte Orchestrion will have a MIDI system
    adapted to it ---  just like every other Welte Orchestrion being
    restored today.  Correct me if I'm wrong,  but I understand the
    Welte at Sanfilipo's has also been adapted to accept MIDI files.
    Contrary to what some say, this does not "butcher" the instrument,
    but the MIDI system is completely unobtrusive and may be removed;
    solenoids lift the original valve lifter wires.  Original Welte
    Orchestrion rolls have been scanned as MIDI files,  and for the
    first time in 46 years,  the instrument will be able to play the
    music it was intended to play (it had been converted to play - of
    all rolls - G rolls!).

    I understand there are plans to retain many,  if not most of the
    other machines that were used in the Anaheim, California,
    Disneyland.  Unfortunately, the "Bear Heads" stay on the Electrova
    Flute Piano in "Bear Country" (one of my pet peeves,  no pun
    intended).

After speaking with Tom Grace, I am confident that he is extremely
skilled and more than qualified to properly restore these instruments.
The installation of MIDI will only open up their musical possibilities
to a whole new generation of potential mechanical music enthusiasts.

S.K.Goodman