|A full shot of Jason before he kills Harold and Edna|
One if the better things about putting these old horror movies on Bluray is that we see never before seen details. Growing up in a VHS era, these movies were always dark and fuzzy to where details were impossible to make out. Ever since these movies have been on DVD, we could make out that Part III has some very revealing shots of Jason's face. But still, they were hard to really see and served as nothing more than teases before the final reveal at the end.
Most of the movie Richard Brooker wore a pull over mask designed by Stan Winston that was not the face that we see at the end. In photo one before he is wearing it as well as photo two. However in photo three he is wearing the final makeup that we do see at the end of the film which leads me to believe that it was shot around the time they shot the ending of the movie.