Robbie commented in 040804 MMDigest [Spool Frames for Style
"O", "A" & "G" Rolls]:

>[ Coinola instruments equipped for playing "A" rolls use the
>[ same spool frame but the spools turn the opposite direction
>[ (i.e., they spin as in other makes of "A" and "G" instruments).

Not necessarily true in all Coinolas.  Coinolas with the spool frame
that looks like the typical "O" roll spool frame play "A" rolls the
same as they play "O" rolls.  The difference is the tracker bar spacing
and the size of the cores.

Some Coinolas used the typical "O" roll frame with two cast iron pieces
that hold the tracker bar forward of the spool frame and play an "A"
roll in the typical fashion as a Seeburg, Cremona, etc.  The third type
of Coinola spool frame for "A" rolls is unlike any "O" roll spool frame
and resembles the large cast iron spool frame in a Cremona but the drive
for spool frame is the typical pulley type mount like the "O" roll
frame.  In every case the roll goes from top to bottom as it plays.

There were _no_ Coinolas made in the factory that played "G" rolls.
Another piano recently showed up in Texas that was sold as an original
Wurlitzer nickelodeon.  Wurlitzer pianos always played Wurlitzer rolls,
and not "A" rolls and not "G" rolls and not "O" rolls.  Only Coinola
pianos made by the Operators Piano Company of Chicago used the style
"O" roll.

Recently in the MMD there was a question about the "O" roll scale
[040801 MMDigest, O-roll Swell & Drum Expression Controls].

The accent hole, number 87, was used to operate a pneumatic on the pump
vacuum reservoir that increased the vacuum level.  This controlled the
entire vacuum supply to the instrument.  Holes number 15 and 16 increased
the vacuum only to the snare drum and operated a small pneumatic on the
tympani beaters in early Coinola "X" models.  The small pneumatic on
the tympani beaters moved the beaters closer to the bass drum head for
softer playing.

The first hole in the Coinola roll is the play hole on the left side
of the roll as you are looking at the roll from the front as it plays.
The second hole that will appear as it plays is hole number 18 that
operates the shutoff pneumatic in the coin accumulator.  The third set
of holes will set the controls that operate the various instruments to
their on/off positions.

On original "O" rolls the top 12 notes are played only when the solo
instrument is used, such as the pipes or the xylophone.  In the 1970's
an "O" roll scale was published that had some incorrect information.
It is best to check a later publication for a correct roll scale.

Don Teach - Shreveport Music Co.
Shreveport, Louisiana