Thanks for the advice, Bob!  The comments that the 6-inch pneumatics
are "too powerful" on high intensity, and not "nimble" enough came
from a user on this list who has one of the best-sounding Ampicos
on YouTube, so I respected them.  (And we likely should respect that
Ampico chose to "shrink" them on later versions, and wonder why --
any ideas?)

The notion that the aluminum washers for valve bodies improves
repetition (not just allows for use of the metal outer valve seats)
came from Mr. Streicher, who surely knows a thing or two.  That
said, as long as the current set-up (excepting the upside down blocks,
which I definitely intend to "modernize") will not cause inherent,
documented problems, I'm inclined to "leave it be".  But I hope that
others with opinions on this matter, and maybe even "hard data", will
kindly step forward and proffer them.

Most respectfully,
Gordon Stelter

P.S.: One thing I am quite happy about on this model is the drawer
lock.  It took me a while to discover why I couldn't readily pull out
the drawer, but once I did, I was delighted!