The only occasion when I have been to a SSPX Mass, when I was still an Anglican priest, was when the family sent Pam and me to Avignon for a week to celebrate our 40th Wedding Anniversary (our 50th comes next year si fata mihi parcent superstiti). I went to Sunday Mass in the exquisite rococo chapel of the Black Penitents.
The Black Penitents, don't you feel, sound rather like something sinister in a Gothick novel by Mrs Radcliff. They were in fact a pious confraternity whose charity embraced those imprisoned nearby, and those sentenced to death. They had the privilege of being able to reprieve each year one of those sentenced for a capital offence.
A couple of weeks ago, exploring Lake Garda by the ferries from my comfortable and hospitable base in the Locanda agli Angeli at Gardone Riviera, I found myself in Desenzano, once the capital of the canton embracing the Southern part of the Lake. Having 'done' the very rewarding duomo (which, in this part of Italy, means a large church, not necesarily with a cathedra ... another old Italian term going back to the first millennium is pieve, meaning a church with a Baptistry), I climbed the hill to have a closer look at the Castle occupying the high ground. A few feet away from it, was a church built as a Chapel of S John Baptist decollati for the the Confraternity of that name. Their charism appears to have been much the same as that of the Black Penitents of Avignon.
Dr C*tt*n will know whether such pious institutions existed in Catholic England. I don't.
(Incidentally, down in the piazza of Desenzano is a Memorial to those who died in the First World War. What struck me was its fierce reference to the salveggia rabbia of the Germans and Austrians. I could detect no evidence that this might have been covered up or tampered with during the years of Italy's Second World War alliance with Hitler. Thought-provoking, yes?)