[nickcarraway]

But if Archbishop Lefebvre signed it, will that lead everyone to question the legitimacy of Vatican II?

(Personally, I don't understand this: I had always heard from all sides that he had signed off on it.)

[NYer]

But if Archbishop Lefebvre signed it, will that lead everyone to question the legitimacy of Vatican II?

Of course not. He simply agreed with its contents NOT with its 'interpretation' by certain prelates.