Hi Darian.
I have both posters as well. FALL BREAK was the intended title, and as you can see, posters were printed with the title. However, it was never released with that title. To make it more bankable (what is a FALL BREAK anyway? No one calls Thanksgiving break "Fall Break"), it was re-christened THE MUTILATOR and given new (and better) art. I read about the film and the re-titling years ago in FANGORIA. Then, many years later (maybe 10 years ago? More?) I bought BOTH posters from a guy on eBay...and it had been the guy who had written the article. The director (Buddy Cooper) had given him a bunch of the posters. I would guess the FALL BREAK poster to be rarer because it was never used. But THE MUTILATOR is much more interesting---and, i agree, probably the more valuable of the two.
I saw this movie when it came out. I went alone. There was a person with obvious mental issues also watching the movie and he kept getting up and standing under the screen and looking out at the audience, rocking back and forth....then he'd sit down for a while before doing it again. His seat? Right behind me! EEEK! Jeepers. Glad this was the 80s. Had it been today, the guy might have had a gun or something. CRAZY!
But cool posters...especially the MUTILATOR one.