Mike Barrier was kind enough to get back to me with the production numbers of MGM cartoons that were actually made that I was lacking, so the filmography is complete in that regard. Mike added this note about abandoned cartoons too:
Rudy Ising told me long ago that the “rejected” and “abandoned” labels shouldn’t be read suggesting that someone other than the director had rejected a cartoon. Those were just the numbers of stories that the directors scrapped before they got very far into work.
Thanks, Mike!
Awesome! We all owe Michael barrier a big thanks for his work and dedication to the preservation of animation history.