I am not familiar with the system used by the Reproduco but, if it's
similar to the Wurlitzer Photoplayer, keep the pipe runs from blower
to instrument as short as possible.  The longer the trunking lengths
the more sluggish the air flow becomes, particularly under demand,
particularly on the pressure side.  The organ will sound breathless
and a certain amount of robbing and bounce will occur.

Even if the initial pressure is raised at the pump end, the resulting
speech of the pipes will be affected.  It may well be possible to
achieve the desired pressures statically, but under demand there will
be pressure drop.

It's the same as sending electricity along a mile of wire the voltage
reads the same at each end, but put a load on and watch the voltage
drop.  The vacuum for the piano is not so critical assuming that the
playing intensities are only at two or three levels.  Obviously the
same rules apply but since pneumatics work in a kind of pulsing way
the drag effect of a long pipe is not so noticeable.

If, however, the blower is of the discus fan type common to church
organ blowing, then running a trunk of 5 or 6" diameter would improve
matters.  But the golden rule, "keep it short", still applies.

Church organ blowers are normally enclosed in a soundproof box.  The
answer may be to take the blowing plant, place it nearby in some form
of soundproof container, and slightly increase the size of the delivery
pipes.

Good luck!

Paul Camps