CathInfo.com

I was taught as a pre VII altar boy and parochial school choir member that the Mass begins with the Introit and the prayers now known as the "Prayers at the Foot of the Altar" are the preparatory prayers before Mass.  I took a look at Fortescue (The Mass, A Study of the Roman Liturgy, 1912), which seems to confirm this.  Father Fortescue indicates that there almost always preparatory prayers before Mass, of which there was a wide variety, and sometimes said in the sacristy or while in procession.  The current form and place (at the foot of the altar) were put into the Missal by Pope St. Pius V.  At a Sung Mass the Introit is typically chanted by the choir during the procession.  At a Low Mass the Introit is recited from the Missal by the priest after he and the altar server(s) complete the preparatory prayers.  I may have been "splitting hairs" and the Prayers at the Foot of the Altar are almost always a part of the Mass, but I was taught that they were the prayers said before the Mass, and the Mass begins with the Introit.

I've never been to a Traditional chapel, SSPX or otherwise, 1962 or otherwise, that doesn't have the second Confiteor.

Maybe some Indult groups follow the 1962 "to the letter" because they have to or something, but I've never been to such a Mass.