Complex sentence: A first draft was completed in 1946, and it is believed that Crowley reviewed it, since a copy was found among his final possessions; however, his death in 1947 put a hold on its publication.
Split into simpler sentences: A first draft was completed in 1946, and it is believed that Crowley reviewed it, since a copy was found among his final possessions. However, his death in 1947 put a hold on its publication.