I'm leaning towards probably fake. It has to be.
But I have a friend who was flipping through random photos somewhere and stumbled across one from the control room during one of the Apollo missions and even when examined closely is a dead ringer for him. He got really freaked out, and if I hadn't seen the photo on a NASA website I wouldn't have believed him either.
So I suppose in theory, it could be real, but I would think that if it was actually real, some random historian would have noticed it a long time ago. And aren't time travelers supposed to make sure they blend into their surroundings? lol