I remember writing about this in 030630 MMDigest many moons ago.
We had one of those rare Harper Electric Pianos at Ashorne Hall.
They did indeed have Kuhl & Klatt internals, however the valve chest
orientation was a little different in the Harper, but this was to
accommodate the pneumatic action that was underneath the keyboard
in the Harper and not above as it was in the Kuhl & Klatt.

We always suspected that the pianos were imported by Harper's from
the German orchestrion builder, but it was always possible that the
pianos were made over here and fitted with actions under licence.

As to the rolls, we had four types.  The Harper and Kuhl & Klatt
rolls would play the xylophone, mandolin and piano expression, basic
as it was.  The rolls marked "Pneuma" and others marked "Reliance"
would play only the piano and its expression.  All the rolls we had
in the collection had wooden spool flanges and the paper was the same
width [340 mm] and scaling.

The Kuhl & Klatt orchestrions were the better instruments in that the
xylophone was of the re-iterating variety and the Harper was single
struck.  The mandolin effects were absolutely magical when set up
correctly because they too were on a re-iterating system.

Hope that helps.
Paul Camps, UK

 [ Jan Kilstra wrote in 971220 MMDigest of an American piano bearing
 [ the inscription "converted into an electric piano by Harper
 [ Electric Piano Company Ltd." and which plays Kuhl & Klatt rolls.
 [ In 030629 MMDigest Brian Chesters reported roll labels that read
 [ "Harper electric piano of Holloway Road in London."
 [ -- Robbie