I noticed in the list of Roman rites given at the start of this thread that there was no mention of the Premonstatensians, who did have their own rite.
I appreciate that the list is a bit of a mess though, because some Roman rites exist only in pre-Trent form, others in a quasi-NO form and still others have both forms.
When I was in the Dominicans there had been attempts to include aspects of the old Dominican rite in the post vatican II Divine Office (compline procesion, marian antiphons and chant). The mass was totally NO, but we had a couple of priests who celebrated the pre-Trent rite privately and one who celebrated publicly (the private celebrators celebrated Tridentine Roman rite when doing public celebrations).
Nowadays from what I understand there are some Dominicans who are including elements of the pre-Trent rite in the NO, such as prior preparation of the Chalice. But this, as with the Divine Office, is by improvisation rather than any actual post-VII revision of the pre-Trent rite.
So it is interesting that the Mozarabic rite etc have been reformed, because the Dom's rite never was (officially).
