The person who "dumbfounded" Mayfair, mentioned in the opening credits, is Sir Stafford Cripps (1889-1952), a Labour Member of Parliment from 1931 to 1950 representing Bristol. As a member of Clement Attlee's government, he was responsible for selling British jet engine technology to the Soviets in 1946.

This film received a landmark color television presentation in Philadelphia, Saturday 6 October 1956, on WFIL (Channel 6), as Ford Film Playhouse's promotional introduction to the new line of 1957 Fords; at this time color TV was still in its infancy, usually limited to special presentations, most often on the National Broadcasting Company's affiliated stations, of which WFIL was not the local representative. Vintage feature films, which may have been original filmed in Technicolor, even comparatively recent ones like this one, which was only seven years old at the time, were not considered worthy of this special treatment, with added costs passed along to the sponsors, so were normally only shown in B&W. In this case, since the film was of British origin, there was not the problem of all the automobiles being of noticeable vintage, since British automotive styles were less familiar to American audiences, and more difficult to date. However, the years had not been kind to the so-called "New Look" women's fashions of 1948-1949 so prominently displayed, and which by 1956 had long since become the "Old Look."

Michael Arlen in the crazy opening credits was said to have confounded Mayfair in 1920. Arlen was a British-Armenian author highly regarded for his cynical romantic novels about post World War I London society. He later wrote a short story in 1940, "The Gay Falcon," that led to a series of Hollywood movies based on the Falcon character. George Sanders played the lead role in those highly popular films.

When Michael goes to bail out Henry from the jail, he tells Inspector Hennessey that the place hadn't changed much. The inspector asks when it was that he had seen him there. Michael says it was when April the Fifth won the Derby. That would have been the149th running of The Derby at Epsom Downs on June 1, 1932. That was 17 years before the time of this film.

This film was the second most popular picture at the UK box office in 1949, behind The Third Man (1949).

This film was made as a follow-up to Spring in Park Lane (1948).

The person noted in the opening credits that "confounded" Mayfair in 1970 is the novelist and playwright Michael Arlen (1895-1956). Born in Bulgaria, he became a "dandy" of London society in the 1920s, and appeared on the cover of Time magazine in May, 1927. Some of his works were made into Hollywood films, such as A Woman of Affairs (1928), The Golden Arrow (1936), and The Heavenly Body (1944).

The plot, involving two cronies who inherit a posh yet financially strapped fashion house, borrows liberally from the 1933 Broadway musical "Roberta," which was filmed by RKO in 1935, and remade by MGM in 1952. Also in keeping with "Roberta," Maytime In Mayfair (1949) climaxes with a lavish fashion show.

The device of a fashion show depicting models springing from life-sized magazine covers of the day originated with Cover Girl (1944), and was subsequently used in this film as well as Easter Parade (1948).

Sir Stafford Cripps, in the opening film credits, is said to have dumbfounded Mayfair in 1948. Many of the British upper class probably were pleasantly astonished at the success of Sir Stafford Cripps, a long-time politician and wealthy barrister. He was most adroit as Chancellor of the Exchequer in helping England rebuild after WW II.

Actor Tom Walls, who plays the inspector, owned and trained the horse that won the 1932 Derby at Epsom Downs. The horse, April the Fifth, is mentioned in this movie. He was a real long-shot win, going into the race with 100 to six odds. He won the race on the straightaway and left the favorite, Orwell (five to four odds) back at 9th place in the field of 21 horses.

Tom Walls, a long-time actor of stage and screen, and renowned horse trainer and racer, plays the Inspector in this film. Walls died 2½ months after the film was released in 1949.

Fourth of six films pairing Anna Neagle and Michael Wilding released from 1947 to 1952.

In joke Michael Gore Brown (Michael Wilding) to Marquis of Borechester (Nicholas Phipps) referring to Judy (Anna Neagle) 'She looks just like Anna Neagle'

When the police are checking the contents of Sir Henry's pockets after his arrest for being drunk and disorderly, one of the items they find is a card for the Michael Wilding fan club. Michael Wilding was, of course, the actor playing Michael Gore-Brown, the lead male character.

The last film role for Tom Walls.

This film received its premiere on Turner Classic Movies on September 23, 2018 as part of a Michael Wilding series.

Features a fashion show by some of the leading designers in the UK at the time, promoting the then revolutionary "New Look" fashions of the era, which enjoyed a mercifully brief period of popularity.