having not read (or seen) The Last Don, or Omerta, that kind of surprises me since I thought Mario & Francis created original storylines for GFII & III. On the other hand, none of all of the material from The Godfather novel was really original, since Puzo based a lot of it on actual events from organized crime history, so it seems logical in hindsight he used elements from his other works to complete the Godfather trilogy it eventually became.