Can someone please enlighten me as to where the rubber O ring goes on the distributor? I have looked in Bentley (for my Vanagon) and Haynes (for my Super Beetle) and from the drawings in both, I can't figure out exactly where it goes on the distributor-FWIW, neither my Vanagon nor my Super Beetle distibutors had this O ring-otherwise I may have figured it out!    Thanks,  Jeff