So in other words, you are saying Archbishop Lefebvre was not a Catholic?
He was being ambiguous. He kind of wanted to have his "EENS cake and eat it, too!" Let's consider all of this in terms of Pascal's Wager:
1) An invincibly-ignorant non-Catholic who has genuine implicit faith and submission to the Roman Pontiff is in a state of grace, that is, no original sin and no mortal, either.
2) A non-Catholic is in a state of original and/or mortal sin.
With respect to non-Catholics, categories #1 and #2 are mutually exclusively. Do you agree? If so, how are we
harming the non-Catholic in #1 by preaching the Gospel of Jesus Christ to that person? How about #2? And, if we cannot tell the difference between #1 and #2, then does it matter? We should preach the Gospel. Period. To every human creator, without exception. Agreed?