Rick Crandall, Matt Jaro and I are currently compiling a database
of original Operators style O orchestrion rolls, and we're trying to
determine who supplied early O rolls to Operators before that firm made
its own.

Some early (pre-"Columbia" brand) O rolls have square holes, and
others have round holes.  QRS is known to have square-punch 9-per-inch
perforators.  I theorize that early O rolls with square holes were made
by the coin-operated division of QRS (as described by P.M. Keast),
while the ones with round holes were made by the United States Music
Co.

Operators seems to have had connections with both QRS and U.S.  Mr.
P.M. Keast said his first job when he went to work at the coin-operated
roll division of QRS in 1918 was to orchestrate O rolls for Operators.
In November 1918, the United States Music Company sold its six-per-inch
perforators, masters, and other equipment for making "A" rolls to the
Columbia Music Roll Company division of Operators, so we know there was
also a connection between U.S. and Operators.

Has anyone ever seen a U.S. 88-note piano roll with square holes?
This would indicate that early O rolls with square holes could have
been made by either company.  If no such 88-note U.S. rolls exist,
that would indicate that the coin-operated division of QRS also
supplied O rolls to Operators.  If you have U.S. 88-note piano rolls
in your collection, especially rolls made before 1918, we'll appreciate
your checking the hole shape and reporting your findings to us via MMD.

Thanks,
Art Reblitz
http://www.reblitzrestorations.com/