Dupré's father was the organist of St-Ouen, and Dupré admired this instrument where he recorded his Symphonie-Passion in the 1960's.
Here is a much smaller and easier piece : some very concise variations on the Christmas canticle "Il est né le divin Enfant" (He is born the divine Child).
0:00 harmonized canticle on plenum
0:43 song at the LH on the cromorne
1:36 kind of a berceuse, theme on the cor anglais from POS coupled to PED
2:22 mini scherzo on REC flutes
2:54 short fugue on plenum and build-up
3:47 micro fanfare-carillon on the tutti.
The plan of the piece, the ideas and the "writing", the harmony are quite representative of Dupré's improvisations on this kind of theme (see for instance the variations on "Adeste fideles" he recorded for Aeolian rolls).