I've been working on a friend's 1917 Adam Schaaf upright player,
and the mechanism doesn't seem to match the ones Player-Care lists as
usually being in this piano.  It uses fingers set into the tracker bar
to track the roll through two pneumatics on top of the roll box.  It's
a two- valve system, and the roll motor uses shared valve sliders.

The primaries are under the roll box, then tubed down on the key side
to the tiers, with the secondaries venting on top of the tiers on the
key side (three-tiered stack).  Although rebuilt in the distant past,
with an added electric box and good note cloth (at least they appear
to be in good shape), the valves are giving trouble and I suspect some
bad pouches as well as valve facings.

It will be some time before I can fit the stack repair into my schedule,
but I was interested in just what action this might be.

David Dewey