The seemingly anti-communist french article where this was …

The seemingly anti-communist french article where this was found gave no mention of who Baruch Levy was, why he was writing this letter or how the author of the article got the letter. Theres 0 reason to believe this was a genuine letter and not just a literary device used by the author to expand on his theories.

But even if it was per chance genuine, who cares unless you can show this was representative of a widely held ideology. Was Baruch Levy a leader, an influential Rabbi in the Jewish community? We won't know because there's no reference to any real verifiable person.