Thought I'd link this. Somebody uploaded Ernest Pintoff's magnum opus, Flebus, with original screen credits. It's still cropped, but it'll do until somebody releases the CinemaScope shorts with the correct aspect ratio on DVD.
I got to see this cartoon last year in its widescreen form on the big screen (projected from Mark Kausler's 35mm print). You haven't truly seen the cartoon until you watch it from film.