Twenty four hours later, and I am still greatly intrigued by this project.
The possibility of publishing any other edition of the missal of the classic Roman liturgy has hardly been considered since the 1962 Missal came back into print. The publication, if it ever gets off the ground, reflects a certain shift in the area of Traditional Catholicism.
As I mentioned, previous to this, no one has seriously considered bringing anything other than the Missale Romanum of 1962 back into print. This is, of course, because the debate over the Latin liturgy has largely been framed as between 1962 and 1970. 1970 is fairly obvious; it is this edition of the Missale Romanum that introduces a new liturgy into the West. 1962, so far as anyone can guess, seems to have been settled upon because that was the edition Lefebvre adopted for the SSPX and it was, ultimately, the last edition of the traditional Latin liturgy before the Concilium embarked upon a course of radical deconstruction of the Roman Rite. To be fair, there is still the matter of the Missal of 1965 to consider, but that is another matter entirely.
It has been known, since at least the 1980s, if not earlier, that there were groups who adopted editions of the Missale Romanum prior to 1962. The reasons for adopting earlier editions may vary. I have heard that one group in communion with Rome uses the Missale Romanum as it stood in 1954. Clearly though, most of the groups utilizing earlier editions of the Missale Romanum are of a Sedevacantist variety. However, in the past few years, there has been a more sober discussion about the Roman Missal as it stood prior to Pius XII's reforms of Holy Week. The discussions were limited to an avant-garde few, but the discussions were happening nonetheless. Granted, it is not a mainstream discussion, but nothing involving a Latin liturgy is all that mainstream to begin with.
So, what to make of an attempt to republish the Missale Romanum as it stood prior to Pius XII's reform of Holy Week?
The idea that we could begin to look to the Traditional Roman liturgy before 1962 is, in ever so small increments, not looking like an absurd proposition. In the aftermath of the Novus Ordo Missae, it is no longer considered taboo to question the wisdom and merit of pontifically induced changes to the Latin liturgy. Interest in the Roman liturgy prior to the Pian reforms is only natural.
This publication, if it ever happens, comes from a Sedevacantist outlet, however. There is a lot to consider here. The potential publisher indicates that, among those who are not in communion with the Bishop of Rome, the Sedevacantist position has the potential to gain ground, if it hasn't already. This puts the line the SSPX is trying to walk into perspective. The position of the SSPX wants to hold that the office of the bishop of Rome exists and is filled by a legitimate successor to Peter, however, it also holds that the successor of Peter's authority is not without its limits. In some respects, the SSPX is forcing a Latin formulation of the Eastern understanding of the Roman papacy; to the degree that the Bishop of Rome maintains the Tradition is the degree to which he has authority. In other words, the Roman Pontiff's authority is accountable to Tradition. Not a precise parallel to the East, but I think the affinity is there.
The fact that a Sede group could make a run a this publication effort suggests that Sedevacantism could come into its own in the following decades. Plainly, there is a contingent among the Traditionalist that do not acknowledge the Bishop of Rome and for whom the position of the SSPX is too compromised. How well this publishing effort goes will provide an indicator of how well Sedevacantism has positioned itself.
In some respects, it is only natural that such a push to republish a Missal that would be a symbolic rejection of the papal authority should happen now. In some quarters, there was disappointment with Summorum Pontificum seven years ago, the conviction being that it did not go far enough and did not genuinely restore the old rite. More recently, Rome has seen an revitalization of certain trends that were hoped to have been put to rest, trends which, for the Traditionalist, are symptoms of Rome's decline.
Of course, there's a few things the publishers need to resolve. How one lambasts the Pian reforms and then proudly notes that this Missale will contain the propers to Pius XII's Signum magnum of the Assumption seems counterintuitive. Nevertheless, this publication if it ever happens, could prove to be an indication that a second waive of Traditionalism is coming, one that, conspiracy theories about conclaves aside, genuinely feels it has no need for Rome...if it ever gets off the ground.