Advice needed -- I looked at a Universal Player piano the other day.
It pumps fine manually, and electrically, however, many notes do not
play and the tracking mechanism doesn't seem to be reading the roll
edges, although I can get it to respond if I place my finger over
the tracking holes.  By testing it with the foot pedals, I suspect
the problem is the failure of the plastic valve pouches, and possibly
the valve facings.

I've gone over the MMDigest Archives but I haven't found much on
the subject.  I'm not used to dealing with the aluminum chests and
I am wondering if there is an article somewhere showing recommended
rebuilding process.

I notice one rebuilder says he uses zephyr skin pouches, but I've
always understood they are subject to bugs eating them.  There is one
rebuilder offering pouch and valve replacement on eBay right now.

Thanks!
David Dewey