Who was the director of the 1964 American musical-fantasy film for which Cotton Warburton is probably best known for editing?
Cotton Warburton:  He worked for the Metro-Goldwyn-Mayer Studios and for the Walt Disney Studios, and is probably best known for his editing of "Mary Poppins" (1964). Mary Poppins (film): Mary Poppins is a 1964 American musical-fantasy film directed by Robert Stevenson and produced by Walt Disney, with songs written and composed by the Sherman Brothers.
Robert Stevenson