Throughout his career Walter Brennan, who had false teeth, approached roles in one of two ways: with teeth or without. In The Gnome-Mobile (1967) he had it both ways: teeth in for D.J. Mulrooney, and teeth out for Knobby the gnome.
The set of the oversize back seat of the Rolls-Royce, along with the Rolls-Royce itself, are on display at the Gilmore Car Museum in Hickory Corners, Michigan. The museum obtained the set through the friendship between Walt Disney and the Gilmore family.
Matthew Garber's final film role. He died at 21 of hemorrhagic necrotising pancreatitis on June 13, 1977 in Hampstead, London, England.
Many of the same special effects used for this movie had been used in Disney's earlier film Darby O'Gill and the Little People (1959).
Ed Wynn's final film role. He died of throat cancer in Beverly Hills, California on June 19, 1966, almost a year before the film was released.