They appear to be the same plant, but I'm not having any luck finding the main name. The hybridizer named it after his wife, Minnie Belle, but he may have shortened it to Minibelle when he named the plant. Is there an Aloe cultivar registry?
I don't know a thing about Aloe's so I'm not aware of a cultivar registry and I couldn't find anything when doing a google search.
Since you found that the hybridizer named it after his wife Minnie Belle, I have a feeling that's probably the correct name/spelling.
I've submitted proposals to move my 2 photos over to the entry for 'Minnie Belle' but there are still two photos of another member at the listing for 'Minibelle'. Perhaps those photos should be moved over too and add "Also Sold As"?
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~ Playing in the dirt is my therapy ... and I'm in therapy a lot!