I don't know if I missed it or not but this bears repeating.  When
bench testing player piano pneumatic stacks, be sure to simulate the
actual installation by putting a length of tracker bar tubing on the
nipple that signals the valve to operate.  The length of the tubing
run from tracker bar to the valve energizing tube should be the same
as the longest tube from the tracker bar to valve chest.

This is mainly a bleed adjustment but tubing length can also affect
valve adjustment as well as bleed size.

Nathan (Skip) Woodhull - S-K Piano
Lima, Ohio