Mike, It's just a personal opinion, but if I were you, I'd be happy with
the earlier version of the Duo-Art mechanism found on your Steck grand.
The so-called "Very Late" version has been greatly over-rated, probably
because of its relative rarity.  Yes, it did have an electric roll-drive
motor, a la the Ampico B; and all the tubing was routed to two large
spring-clamps at either end, which greatly facilitated the removal of the
piano action for servicing; and all the control -- such as they were --
were located in the spoolbox.  All well and good.

However, the price one paid for this break-through technology was the
loss of all the individual, hand-controlled expression levers found in
earlier versions of the D-A, which allowed you to add your own expression
to the rolls being played and thus become a part of the music-making
process, rather than just remaining merely an observer and listener.

If all you want to do is to listen to a reproducing piano play, then you
might just as well buy some recordings of one and save yourself the time
and expense of rebuilding and maintaining one.  OTOH, if you want to
become part of the music making process, that is inject part of yourself
into the music being played, then you'll probably be happier with the
type of D-A mechanism found in your piano.

Some people are undoubtedly happy just to sit back an listen to the music
being played, but I have always considered one of the main fascinations
with the player piano to be the fact that it could make a de facto
pianist out of someone who didn't play, by allowing them to participate
in the performance of a piece via the expression and tempo controls.
Just one old tech's opinion, of course!

Les Smith
lessmith@buffnet.net