Clay Liston Mini Poster / Handbill?

[jpoff430]

I bought this recently and have many questions about it. Of course my first question is whether or not this is an authentic piece of boxing memorabilia associated with the promotion of this fight. These original onsite posters are very rare so there have been many reproductions. The thing that is really making me nuts is the fact that this measures 11 x 7". The original posters were twice this size. So obviously it isnt one of those. Ive done some pretty extensive research and I cant find another example of an original or reproduction that is 11 x 7". The other thing about this is that it genuinly appears to be old to me. And if this is a reproduction, wouldnt they have produced enough that you'd see some around? If anyone has one of these or knows anything about it I would be very appreciative. Im a boxing collector and I just would love to know what I have here. Thanks so much for any insight.