It's easy to do a change-over from a totally electric Duo-Art upright
expression box to a pedal-electric.  There are good pictures of the
configuration the Duo-Art book that Frank Adams [AMR, Seattle, Wash.]
put out some years back.

Basically, when you split it open to replace the Theme valves,
you replace the top section with the proper top configuration (see
the pictures in Adams' book).  If you have a reasonable amount of
experience, and use traditional materials, its easy.  I've done it.
I have one here in Santa Rosa, California, if you're in the
neighborhood.

Oh, the little steamboat vacuum pump fits in just right next to the
foot pedal assembly, as does a 15-inch box pump.  Put the electric
motor on top, mounted in springs like they did on the little Recordo
grands.  You will probably want to change how some of the levers work;
that's easy too -- new rods are available at any hardware store.

You won't find much space left over below for a Reroll pneumatic,
so you might follow the early Duo-Art lead and have the Reroll hole
shut off the motor.

Bruce Grimes