The use of a Crucifix in entrance and exit processions, and the use of gloves with which to handle the Crucifix are ... examples of matters of custom. It might surprise you to know that a Crucifix is only required in Pontifical Masses.The Tridentine Community News, July 27, 2008 (St. Josaphat Catholic Church, Detroit), from which these excerpts are quoted, is always full of delightful and edifying detail concerning liturgical tradition. This issue was the second of three installments devoted to Liturgical Law, Canon Law, and Custom.
... Virtually everyone applauded the P.C.E.D.'s [Pontifical Commission Ecclesia Dei's] decision to allow laymen who had been Instituted as an Acolyte to serve as Subdeacon in a Solemn High Mass. Such a "straw" Subdeacon may not wear a maniple, because he is not admitted to the clerical state. By making this allowance, the P.C.E.D. has made available Solemn High Masses in ore places than would host them if the Subdeacon had to be only a Deacon or a Priest. No one is forced to take advantage of this ruling, yet it does benefit many groups.
On the other hand, virtually no one nowadays thinks that the 1958 papal decision to permit (but not require) the congregation to join in singing the Pater Noster with the priest was a good idea. It is not the norm, and indeed in one local Tridentine Community, actually caused a significant amount of controversy when a celebrant wanted to impose it.
It is always safest to stick with the norm. Our Mass should and does follow the 1962 Missal, just as our Holy Father wishes.
[Hat tip to A.B.]