This is my first time posting on here and I'm not very computer
savvy yet so bear with me.  On the subject of sealing valve pouches,
occasionally when needed I've use a mixture of silicone sealer thinned
with lacquer thinner.  I couldn't say the exact proportions of what to
what but kind of by feel.  By thinning it out the mixture was very thin
and flexible when cured and didn't seem to negatively affect the action
of the pouches at all.  The pouches had plenty of speed and repetition
and valve lifting power.  It seemed to do the job so well that I never
had reason to search for anything better.

Also having to do with bleeds.  On an M. Schultz I did years ago,
the original material that they used on the small hook pouch pneumatics
that are used to open and close the valve which activates the large
pneumatics was made out of an ultra thin rubberized cloth, thinner
than the cloth now used on pneumatics.  That specific cloth was not
available at that time so what I did was cover it with ultra thin pouch
leather.  If I left the leather untreated I found that you could close
the bleed cups completely and the porosity in the leather would
basically take the place of the bleeds.  It had excellent repetition
that way equaling how it worked originally.

I'm almost eighty-six years old and have been working on players since
the mid 'fifties.  I've just discovered the MMD recently and enjoy
reading all the opinions expressed.

Arnold Neuhaus - Neuhaus Pianos
West Allis, Wisconsin