Welcome, Klassy...and enjoy apf...
Your poster is a collage (and not film-title specific). In looking at your poster, there doesnt appear to be any printer's info or other markings (that I can see) on the bottom or any other borders. It also looks like it was attached to a thicker piece of layered cardboard that is now separating a bit at the top edge (per your one image).
Maybe this was made by a local artist somewhere and a small number was produced. The images of MM, and the others as well as the text are all meant to mean something as a whole.. but what that is, remains a mystery..lol.
Just to be sure.. is there any fine print along any border? Or maybe the artist's name written somewhere--maybe more hidden near the bottom or edge? If so, this could help solve the mystery of your poster.
Jeff