Graham Code inquired about adding a Red Welte system to a Licensee or
Green player. (Hi, Graham!)  While I've never done it, the Jim Miller
Vorsetzer that played Duo-Art, Welte and Ampico rolls indicates that
just about anything is possible.

I think the Red/Licensee would be the easiest: they both use the same
lock and cancel expression valve system.  This would require a Red
[T-100] tracker bar, teeing into the Licensee tracker bar control lines,
and some type of mechanical switch that turns one tracker bar on and
the other one off.  Ken Caswell once had a Red Steinway that also
played some other system using dual tracker bars, as I remember.
Perhaps it's still out there?

The Green/Licensee would be more difficult since the Green expression
valve system is like the Duo-Art: the valve is on as long as the
expression holes are present, off when not (no lock and cancel).
But again, the genius of Jim Miller came through about 25 years ago:
he added the Licensee capability to a Green Bechstein that currently
resides in Texas.  The mechanism involved a pair of pneumatically
actuated sliding channel blocks, much like the sort of thing the
upright Licensee Welte uses when going from 88-note to Welte.

So Graham, it's possible.  I can find Jim Miller's phone number if you
want to call him to discuss the installation.  He may or may not be of
some help, given the time span.  I also can find the address of the
fellow who currently (as of three years ago) is the proud owner of the
Green/Licensee slide blocks.  (I removed then from the Bechstein about
six years ago).  The Bechstein is a lovely piano; enjoy!

John McClelland