David,
This letter is from Msgr. Arthur Calkins of the Pontifical Commission “Ecclesia Dei,” and is addressed to Una Voce America; the request was also apparently made that Una Voce post the letter on its public web site. The letter contains a copy of Msgr. Perl’s response to an individual’s questions about the S.S.P.X. I would submit that the publication of the answers to a wide audience may be reasonably inferred as an intent to establish general principles for anyone wishing to assist at Masses of the S.S.P.X. for reasons of devotion. Obviously you disagree, but in the absence of further clarification it does seem that the P.C.E.D. published these answers for a reason. If you believe that these answers were intended to apply only to the questioner, why did not Msgr. Calkins make this clear in his letter to Una Voce? In fact, Msgr. Perl says, “was intended as a private communication dealing with the specific circumstances of the person who wrote to us,” which is in the past tense; whether that refers merely to the time the original letter was sent, or to whether the advice was only for a specific set of circumstances, is unclear.
What does seem clear is that reasonable people could infer wildly different things from such a communication and its method of distribution (the Una Voce web site). As I said previously, a simple note from the C.D.F. could eliminate all doubt on both sides.
–Paul