The film Gerald Potterton did animation work on came out in what year?
Gerald Potterton:  He is best known for directing the cult classic "Heavy Metal" and his animation work on "Yellow Submarine". Yellow Submarine (film): Yellow Submarine (also known as The Beatles: Yellow Submarine) is a 1968 British animated musical fantasy comedy film inspired by the music of the Beatles, directed by animation producer George Dunning, and produced by United Artists and King Features Syndicate.
1968