My thanks to both John Tuttle and Craig Brougher for their suggestions
on regulating my Pratt-Read player. I sure did start something there.
I do appreciate the responses to my query; I only wish that I had done
more research before posting the query.

I found the movement limiting buttons for each pneumatic on the player
mechanism.  They are mounted to a strip of wood above the pneumatic
shelf on the player.  When the player is removed from the piano, there
appears to be no limiter on the movement of the pneumatics (they can be
closed completely).  The pneumatic limit buttons only function when the
piano action interfaces with the player mechanism.  That is what threw
me.

I've already adjusted several notes (I don't get to spend much time
each week on this piano due to family activities, work, house chores,
etc.).  I think I get it.  I knew the problem was not in the piano
action because the notes all played very nicely by hand.  The
pneumatics were allowed to close too far, forcing the piano action
upward so that the backchecks were hyper-extended and holding the
hammers to the strings (lightly) on some notes.

Many thanks,

Larry Toto