Regarding Steffen Just's request for details [230322 MMDigest]:

The Hershell Carrousel Museum in North Tonawanda, New York, owns and
operates the Wurlitzer organ-roll perforators, still operating from
original stencils. It's a superb installation. Its setup works much
as any piano-roll operation would have done although there are some
differences to build paper-acceleration [compensation] into the organ
rolls.

The entire Moller organ-roll production equipment survives, now with
Kegg Organ Builders in Hartville, Ohio.

As far as I know the only original-era equipment still in use for
piano-roll production are the Ampico perforators run by Keystone
Music Roll Company in Bethlehem, Pennsylvania, and (perhaps, if
reinstated after its move) the double-gang perforator run by QRS in
Seneca, Pennsylvania. None of them use original stencils but are
operated from computer files.

I know there are a number of original-era machines in the USA, many of
them Acme perforators collected in the 1980s by Don Rand and reported
in the AMICA bulletin, but their present whereabouts I don't know.

The last traditional piano-roll perforation operation was Mastertouch
in Sydney, Australia, which used card stencils right to the end (even
though they mastered these by computer). The equipment is in store at
Powerhouse Museum in Sydney.

The QRS historical equipment can be seen at the Music Instrument Museum
(MIM) in Phoenix, Arizona. The 1960-Aeolian 'marking piano' can be seen
at American Treasures (the Aeolian perforator was exported to Australia
some years ago, but its Mylar stencils survive).

The Musical Museum at Brentford owns an original Aeolian 88-note
perforator from the Hayes (London) factory, and the relics of a 65-note
machine. The 88-note perforator was converted to make 1-to-1 copies in
the early 1950s, and no other factory equipment is known to survive.
The perforator is on loan and not to be viewed at Brentford.

Aeolian's roll factory at Hayes was photographed in fine detail around
1910, and I included scans from the high-quality photographs held by
Brentford in my 'Meloto dance rolls' catalogue published in 2021 by
the Player Piano Group (available to purchase from the PPG or some
bookshops (ISBN 978-1-9168739-0-2). I described briefly how the process
worked.

Aeolian described their blank stencil paper, as used by its roll editors
to transcribe music, in Reginald Reynolds'  'How to make music by the
means of the Pianola' booklet (widely copied), and a surviving fragment
of it from Frank Milne is shown in my catalogue thanks to Art Reblitz.
The photographs show the stencil-paper printing machine, and the
stencil-duplicators, as well as the editors marking stencils and boys
punching holes through these markings.

Anybody interested in what kind of things roll-editors considered when
making 'arranged' rolls should read Adam Ramet's article, 'Writing /
creating new music rolls for the player piano', published in the PPG
Bulletin and reprinted in the AMICA Bulletin November/December 2019.

Julian Dyer