Thought Factory was a commercial poster producer and released several variations of posters for bigger-budgeted films.
C.K. MacLeod Collectibles has one of the other versions (and I believe they released 4-6 diff CE3K) for sale here at $24.95.
http://ckmaccom.startlogic.com/product_info.php?products_id=10530While some were machine-folded (like yours) for promotional mailings, they were widely sold rolled.
MacLeoud also has other titles from Thought Factory, like THE DEEP and KING KONG 1976.