Thank you to all who responded to my query on PPCo., stock #1117.
Having seen these items I now finally understand Art Reblitz'
comment in his book about never gluing the shiny side of leather.
Now then, how about the atmosphere valve facings, #692?

I am also trying these for the first time.  They are 11/16.  They
appear to be newer material discs faced with a smooth leather somewhat
thinner, smoother, and darker than the original sheepskin.  The discs
also have a no leather insert to grip the wire stem effectively.  In
fact the hole in the disc is relatively quite large - 1/8.  The hole
in the leather is small, but not enough on its own to hold the disc in
place firmly.  The disc moves vertically upon the stem far too easily.

What are the options?  I feel inclined at the moment to glue the new
discs back to back with the old fiber ones, thus achieving the flexible
rigidity of the original assembly.  Or am I missing something?

Roger Waring - The Pianola Workshop
England