Yes, I have been to Play-Rite many, many times and sometimes stayed
overnight.  I saw the roll making operation but I never asked to learn
how it was done.  There are two or three different methods in the
arranging.  I believe these have their limitations.

When I add 'grace' notes there are different degrees of how far the
grace note is ahead of the main note, and how long the perforation.
I can time these to finer than one thirty-second of a inch.  In my
roll SB-6 I add grace notes to the gavotte ("Les Cloches de St. Malo"),
not all through the piece, and in the tune "Il Bacio" mainly in the
last melody.

One another comment.  The shipping company I worked for changed
ownership in 1975 and the new CEO came down to the engines room and
I gave him a tour.  At the end of the tour he asked, "Do you need
anything?"

I said, "A small lathe," and the next day in Skagway, Alaska, a lathe
came down.  Without that, I could not have made my Pistonola piano.
It was lots of lathe work.  Then I made my perforator, all in my
off-watch time, and in the company's time I did ships work machining
valves.

Steve Bentley - SB-"O" Rolls
Vancouver, British Columbia, Canada