I recently bought a Hawthorne that has the basic "Fastback" frame. When I first was on the prowl for it I too called them Zep's, I quickly found that not only was mine not a Zep, many whom I asked didn't know the details either. I'm going to go back and re-read these thread to find out more. one this I do know is "real" Zeps are out of my bike price range. I love my Prewar Hawthorn but want to eventually make a partial trade for a Colson with a tank , carrier and the famous turkey wing...love those bikes...