The film, which was to be directed and designed by John Hubley, was one of the numerous film and TV projects shelved as a result of the Congress-approved House Un-American Activities Committee and their "Inquiry into Hollywood Communism."
All that remains of the film are 400 storyboard sketches that recently surfaced. Cartoon studio United Productions of America (UPA), known for Mr. Magoo, was to have produced the animated picture.
According to an article for Print magazine by John Canemaker, republished on animator Michael Sporn's blog, the storyboards were recently discovered after careful storage by UPA's president Fred J. Schwartz. Animation industry rumors also indicate that there was once a full-color storyboard (now alleged to be lost) and a "dream soundtrack," never publicly released, featuring Frank Sinatra, Ella Fitzgerald and Louis Armstrong, among others, and original Finian's cast members David Wayne and Ella Logan.
Character sketches of Finian McLonergan himself, and Og the Leprechaun, among others, were also uncovered, as well as a storyboard for the song "Something Sort of Grandish." These sketches and storyboards are published on Sporn's blog.
— Allison Klamkin