There were only two films shot in CinemaScope 55, The King and I and Carousel. They have both been released correctly formatted on DVD. All other 2.55:1 CinemaScope films were shot on 35mm film without an optical soundtrack, hence the wider than usual aspect ratio. Smileboxing is only suitable for 3 panel Cinerama films. I don't think it is an appropriate way to show any other widescreen films. They simply weren't intended to be shown on screens with really deep curvature like proper Cinerama screens. Smilebox is simulating the curvature of a proper Cinerama screen (147 degrees). CinemaScope films were never intended to be shown on screens curved that deeply.