Here's a snippet from a book I randomly happen to own a PDF copy of about him:

Rough translation:

Unharmed, the Nordic Faith Community of Wilhelm Kusserow survived the denazification because he wasn't a member of the Nazi party. Additionally, he managed to be perceived as a victim by authorities, thereby avoiding post-war reeducation in interment camps. Afterwards he founded the Artgemeinschaft e.V. [rest of name] which adopted almost the same creed as the former Nordic Faith Community.