In response to Bob Taylor's essay, is there some good reason to have
the lifter disc in an Ampico valve glued to the pouch instead of the
bottom of the valve stem (perhaps with a very thin piece of felt on
the pouch side)?

It seems to me that if it were the stem, it would remove the variable
of different-sized glue-blobs on the pouch-to-lifter-disc interface
that can alter pouch flexibility.

Gordon Stelter