The Reproduco pumps I've seen all are quite unique.  The one I have has
a fairly standard 4-bellows pump for vacuum.  (Interesting in that the
"connecting rods" are made of canvas layered until it is about 1/4"
thick, and runs absolutely silently--quite a good use of sound and
shock absorbing material)

The pressure on the Reproduco organs requires two different pressures
about a full 2" apart: four inches for the pipes and six inches for the
organ action.  So they used static pressure for the high pressure and
regulated pressure for the pipes.  If you have need for more
information, just email away.

Bill Chapman

P.S. I pronounce it ReproduSo, not ReproduKo, though there seems to be
quite a bit of variation on pronunciation.