Earle Hennagir has a few questions about a Marshall & Wendell Ampico
[080810 MMDigest].  I have an earlier Marshall & Wendell Ampico 'A'.
These were the "budget" line from Chickering and have an enormous
sound.  I am very happy with mine and they are definitely worth saving.

As to which system to use, it's an issue of practicality.  The
later-style (Ampico 'B'?) valve blocks are pretty nice if you can keep
the ball valves clean and eliminate the need for intermediate valves,
so the system is simpler to fix and maintain.  The transmission frame
is (or it used to be) available from Player Piano Co. (PPCo).

I am puzzled by a ratchet-spring motor, though, I can't imagine that
it would go for very long pulling a load like the bellows.  Was this
original?  And is perhaps the expression mechanism 'B'-based?

A. B. Bonds