The "Fountain Pen Sketch" was taken from the hit musical (over 400 performances) that opened in New York in 1948, and starred Sid Caesar. Max Showalter, who performs that specialty number in this movie, was also in that opening night cast playing the same role, as well as others.
In the audition scene with Virginia Mayo, Berle imitates an upper-crust type, wearing a monocle and a robe or smoking jacket with an Art Deco-esque print. This unusual-looking garment was used in a movie at least once previously. It was worn by Monty Woolley in The Man Who Came to Dinner (1942).