That entire theory is based on an emancipation act for someone who had one of the most common first names of the era? And that this person might or might not have come from an area with a Jewish population higher than in other areas? I'm not saying he has a book to sell, but... Hell, I'm saying it.

Also,that might be an unpopular point of view, but unless he was raised in the Jewish culture, he wasn't Jewish even if the claim was somehow true. Perhaps ethnically half-Jewish.