Hi all, and thanks for the advice.  Here is some more information.
I have been doing this since 1988 so I am not exactly new to it.

The man was happy with the piano until very recently when the
expression stopped working because the cloth just failed completely.
The piano had been rebuilt completely some 12 years ago in the US.
The job is not superb and lots of details are not nearly as good
as I would have done them, especially on the piano action, but hey!
It works and he was happy.

All I did was remove the expression box, rebuilt the accordion
pneumatics, adjusted it all for proper travel, spill etc. and
re-installed it.  The 0 accompaniment vacuum level was 3" before
I started and now it is 3" again.  The theme is 4".  These are
difficult to set because the piano action is very uneven and the
notes don't play nearly at the same loudness for a given pressure.
That, however, was exactly the same before.

The spill pressure was very high to begin with at 35" but it is the
same now.  Nothing else could be measured because the accordions
were not working.

As I mentioned, to my ears, it is okay and has a very large dynamic
range from really soft (I couldn't ever play that soft) to banging loud
on level 15.  Over and above this, he also moved the piano to a
different place in the room.

So, I don't know what else to try.  One can only adjust or improve
something if an actual problem is identified and I know he is super
fussy and blind at that.  I am not sure what he means by 'It isn't
right.'

First he was very unhappy with the 'pianissimo not being there'.
I then put in another roll that actually plays pp and showed him that
if it plays any softer, it won't play at all.  He then changed to
stating that it sounds way too loud in places as well.  I then showed
him that the passages he indicated are indeed playing very loud because
they are on level 15 theme.

Then he listened to a couple more rolls and phoned me the next day
saying that the piano was simply to 'rough' and not usable as it is
now. That is where I am stuck at the moment because I am not able to
translate 'too rough' into any adjustment modification.

The only idea I have is to somehow flatten the response curve a little
so levels above 10 are slightly softer.  How about less spring tension
and a new 0 setting thereafter?

As I said, the tests pass as is and everything works nice and fast.

Kind regards,
Bernt Damm
Cape Town