Here is the Regensburg organ in reflective mood. This meditation seems to be strongly influenced by the compositions of Jehan Alain, such as Le Jardin Suspendu - see e.g.
https://www.contrebombarde.com/concerthall/music/27308
As is typical of this style of French organ music, Durufle gives very specific directions for registrations throughout the piece, which I have been able to follow at Regensburg.
Durufle taught many significant organists of the period, including Jehan Alain's sister Marie-Claire.