According to
https://www.catholic-hierarchy.org/bishop/sordb2.html there are 22 bishops still living who were consecrated in 1969, five consecrated in 1970, twelve consecrated in 1971, etc. I guess it is possible that Fr. Ward went to one of these bishops to get consecrated, but the question is, why the silence? I mean, for the sake of the argument let us say that Bp. Jayme Chemello (91 yr. old) in Brazil consecrated him; would this bishop really be opposed to Bp. Ward revealing this? I assume that all retired bishops are in the
Annuario Pontifico. I do see that one of these bishops, provided they were consecrated using the old form, might think to themselves, "Fr Ward, I am consecrating you, but don't let this get out because I do not want to deal with Francis."