In the copper vrs brass hero thread, there is a link to a ton of photos of the original props. The ESB graflex shows round top Philips head screws at the base of the grips and flat head screws on the sides of the grips on top. Again, we all know this could just be another version or one that hasn't been showed in the movie.
The phillips ones are original. The slotted ones were a post production addition, as well as the brass lever screws as far as we can tell.