When I read with interest Ben Willis' posting on this topic,
I followed the link to the example he included.  Once there I read
all the discussion and immediately thought, "Egad, how is anyone
ever going to write an algorithm that will accomplish this".  Oddly,
the discussion seemed foreign to me even though I wrote it.

My comment is, if someone can make new rolls, that would be great.
The main obstacle is understanding the Ampico (or other system) coding.
It is very complex and often oversimplified by [software] emulators.
Most ignored is the fact that the Ampico "A" system works in a fashion
very similar to the three pump stages found in the "B" system: the pump
can have no amplification, partial amplification or full amplification.
Control of those stages in the "A" system may fall to the unused side
of the stack at a particular instant.

It would be much easier to choose the Duo-Art system as the beginning
for this project.  It, too, has complexities that aren't explained in
most discussions, but they are easier to convert to algorithms.

A recent YouTube posting demonstrates the roll coding and modern
recording that originated with the Stahnke laboratory instrument.
The Stahnke recording piano used is far more sophisticated than the
typical MIDI recording piano.  The recording of the Rachmaninoff
"Prelude in B Minor", played by Leo Podolsky, can be heard at

  http://www.youtube.com/watch?v=-0OjVHOL0Qo 

At one point in the video, the master roll with all edit markings,
can be seen playing the piano.

Bob Taylor