[NYer]

Williamson basically passed through the Catholic Church on his way to the SSPX from Anglicanism.

Thank you for pointing this out ... it caught my attention too, when I read the original post.

A question ... What drew Williamson to the SSPX in the first place?

[Theosis]

"What drew Williamson to the SSPX in the first place?"

Many SSPXers I know have wondered the same thing.