Hello Jonathan,
thanks for your your comparison of both instruments and thoughts about licensing philosophy.
The Ducroquet-CColl and the Metz Mutin-CC are different instruments and both have their special area of music, which can be played.
As stated earlier in the organ history introduction
http://www.organartmedia.com/Aix-Intro.html
the Ducroquet-Cavaillé-Coll is a transitional romantic-symphonic instrument with both roots in late Baroque and early romantic.
Due to the Cromorne (!), the Sesquialtera (!) and the brilliant Fourniture and Plein Jeu, which are normally not existing or have a darker colour within Cavaillé-Coll organs, one is able to play the complete (French) organ repertoire, beginning from late baroque up to modern pieces.
Both instruments represent typical French symphonic sound and the customer has to decide due to his preferences.
I have no objections against comparative recordings on Contrabombarde.com concerning the DCColl, would be an interesting thing.
PS:
Concerning Bombarde 32 feet:
I didn't realize that for the DCColl by intention, because it doesn't fit to this instrument type and size.
The Bombarde 32 feet rank, which is very difficult to build and to voice (CColl himself was a master of this), only will be found on a few big CColls (usually > 60 stops).
Extended ranks on the Ducroquet-CColl are only those, which could physically be found and realized in practice in such an instrument. The virtual Basse acoustique 32 (with a 10 2/3 rank) makes a great effect for this organ.