There is a very basic answer to the abbreviations O.S. and N.O.S
in conjunction with the Reproduco Instrument.

The Operators Piano Company of Chicago built many instruments for use
in public places.  Most notable was the "Coinola" line, and the one
using a Style "O" music roll, was their most complex and probably in
answer to the Seeburg "H" and Cremona "M".

Reproduco rolls were made by the Capitol Roll & Record Company (also
just "Capitol Roll Co.")  The Reproduco instrument was made in three
basic sizes as to pipes, voices etc.  All used the same music roll.

Now to the answer of the main question: "O.S." stands for "Organ
Series", "N.O.S." stands for "New Organ Series."

The N.O.S. rolls were played at half the speed of the O.S. rolls, which
meant that the same number of feet of paper on a roll would play twice
as long.  This was important in a funeral parlor where a long and
frequent pause in the music did not always happen at the most opportune
time.

All Reproduco organs could play both styles of rolls.  It was a simple
matter of changing the belt from the motor to the spool frame, on a
step pulley.  The O.S. roll played on a ratio of one-to-one.  The N.O.S.
roll played on a ratio of one-to-two.

You could, of course, purchase an instrument with a duplex roll frame,
so it mattered not what series of music roll you used because you were
guaranteed continuous playing.

The Reproduco seems to be a "sleeper" among collectors, probably
because it does not have flashy coloured glass and carvings.  While
they do not look showy, they make wonderful, easy-to-listen-to music.
Just one drawback: there has not been a re-cutting project for about
thirty years and good music is very hard to find for sale.

Best to all

Ken Vinen -- Enjoying my Reproduco in
Stratford, Ontario, Canada