This 1943 Warner Brothers’ Merrie Melodies animated short is entitled Coal Black and De Sebben Dwarfs. It is one of the so-called “censored eleven,” cartoons that were taken out of circulation by their then-owner Universal in 1968 due to their questionable subject matter. It is pretty plain as to why this one would be suppressed–its vile depiction of grotesque black stereotypes (and, this being wartime, at least one mention of “japs”). What surprised me is the Citizen Kane reference.
Note: I prepared this post a few days ago with a youtube video that claimed to be taken from a 16mm print with very good image and sound but that has been removed. (I guess Warner Brothers only want people to see this if it is a mess of a VHS rip.) I settled on an inferior video. If this one is removed you’ll have to try your luck here.