On Mike Meddings web site (http://www.doctorjazz.freeserve.co.uk) there
are several illustrations of J. Lawrence Cook at a marking piano.  See
the JLC page and the photo gallery.

This instrument has a double keyboard, and is quite different to the
well-known recording piano at QRS.  There is strong evidence that these
photos were taken while JLC was working for Aeolian in New York in the
1960s.

I tried to look up more information to see whether the photos match
others taken at Aeolian.  However, I failed to find any reference to
Aeolian's operation of this era in the books I have got.  Can anyone
provide further information or photos, or suggest where they may be
found?  I'm sure there must be MMDers who visited and maybe took
photos.

Julian Dyer