Prélude Funèbre is number 10 of Lemmen's École d'Orgue, basée sur le plain-chant romain. Lemmens precribes a Bourdon 8 and Basson 8 for the left hand. The Cracov sample set doesn't have those, but it does have a Bourdon 16 and Basson 16. So I used those and played the left hand part an octave higher than notated.
Cracov, St. John Cantius is a sample set made by Piotr Gabrowsky. It is a free set. More info and download at: http://piotrgrabowski.pl/cracov-john-cantius.html
SCore available at imslp: http://imslp.org/wiki/Special:ImagefromIndex/130907