Posted By:
Andy CookLeon,
You're wrestling with one of the great issues of our day. On a related note, how are blank backed "E135s" referenced? That may be a good guide. I think the answer is which set - E121 or W575 - do we consider as the root set from which the others are derived? I consider E121 as the root, which spawned W575 and thence all the off shoots - Witmors (3 types), Leader Theater, Holsum (2 types), Haffners, Gasslers, Gertenrich, Herpolsheimer. Therefore I vote E121.
Andy