Here is a photo of Montbeliardii that I took circa 1974 at Longwood Gardens, PA:
The man is my father. Does this photo look familiar to you?
Here is a photo of Maurelii that I grew in 2005:
Lately, I have been seeing a lot of Ensetes that look intermediate between Maurelli and Montbeliardii:
Here is an Ensete at Garfield Park Conservatory, Chicago, IL in 2003:
Compare with Ensetes here:
https://www.houzz.com/discussions/33...nanas-etc#n=18
I suspect that these intermediates might be seedlings of Maurelii.
Incidentally, Maurelii can be propagated by decapitating just below the meristem. The cut surface develops callus tissue that looks like cauliflower and then dozens of plantlets grow out of the cut surface. It is risky but I successfully did it once.