CathInfo.com

Excommunication is applicable only to individual people, not to religious orders, foundations, or organisations.  

Though of course said motu proprio included the vague, "Everyone should be aware that formal adherence to the schism is a grave offence against God and carries the penalty of excommunication decreed by the Church's law."

I am concerned about enjoining myself to any movement that is truly in schism, but for my life, I cannot find any ill intention on the part of Archbp Lefebvre. He is very clear that he did what he did to secure tradition. I may be wrong, but it is my belief that Archbp Lefebvre did nothing schismatic and is not at fault, and the Holy See needs to admit that.

Are you concerned with being separated from the perverts and heretics in  control
in Rome, or you concerned with being separated from the Roman Catholic Church? The answer may seem obvious-- but it may not be. If you want to be in union with the modernists (aka heretics, aka conciliarists, aka new churchers) in Rome, then , join up with the SSPX, for they are decidedly headed in that direction. They have already professed agreement with  95 % of the Vatican Council; they have already agreed with the notions of Religious Liberty, with Collegiality; they have already accepted the legitimacy of the Novus Ordo mess, they have already stated they accept all the heretical teachings of Paul VI, John Paul, Ratzinger, and now, Bergoglio.

    If , however, you want to be in union with eternal Rome, the Rome of the Holy Catholic Church, and the Rome of the Holy Catholic faith; in union with the two thousand years of Catholic Church teaching, and, of course, in union with Archbishop Marcel Lefebvre, then you have to stay away from the SSPX. You can find Masses celebrated throughout the country by brave (former) SSPX priests,
like Fathers Hewko and Pfeiffer ( who have been unjustly kicked out), which maintain the true Mass. There are also a number of other priests throughout the country who offer the true Mass. ( CMRI priests, SSPV priests, priests associated with Bishop Sanborn, Bishop Neville, Bishop McKenna, Bishop Morello, etc).

    There is no reason for you to be concerned for your faith if you stick with these priests following true Catholic doctrine. If you stay with the SSPX, headed by Bp. Fellay, which used to follow Archbishop Lefebvre, then you have to be concerned for your faith.