I also recently purchased a poster that supposedly was in the window of the movie theaters when star wars first came out. On the bottom it says: Tribune Showprint, Inc. earl park, Inciana. The poster is in a plastic envenope. I would like to know if this is an original.

I can't say definitely "yes", but I grew up in Earl Park, IN and I remember that "print factory" always had posters in their windows which actually faced the west.