VICE VERSA (1948), a sort of proto-FREAKY_FRIDAY story about a father and son switching places, is a delightful British comedy in the vein of, perhaps, KIND HEARTS AND CORONETS (1949), brought to you by theatrical Renaissance man Peter Ustinov, who wrote, produced, and directed the film (but does not appear on-screen).
The action is set around the turn of the century and involves a magic wish-granting stone, stolen from a temple in India. When young Dick Bultitude protests being sent back to his boarding school, his blustery father (holding the stone) makes an off-hand remark about wishing to be young again. Soon the elder Bultitude finds himself in the body of a schoolboy, the spitting image of his own son. And Dick grabs the stone and wishes to be grown-up, filling out the body of his middle-aged father. Understandably, everyone mistakes Dick for his father and vice versa, sending the father off to school in the boy's place and leaving the son to manage the father's affairs at home.
The dual performances by the two main actors are superb, with an adolescent Anthony Newley (later to star in DOCTOR DOLITTLE and write songs for WILLY WONKA & THE CHOCOLATE FACTORY in a varied entertainment career) doing a spot-on imitation of Roger Livesey's Bultitude Sr. and Livesey in turn acting believably childish as a boy in a man's body. Each actor gives such a distinctly different performance after the body swap that it's no trouble believing that Newley IS a fifty-year-old man or that Livesey IS a boy of fourteen, despite the absurdity of it all. And from there the hijinks are a lot of fun.
Ustinov's film has a wonderful flair for comedy, from the charmingly old-timey title slides to the bookending narrative device that breaks the fourth wall, inviting the audience into the Bultitude home. The literate script uses stuffy British propriety to humorous effect, particularly through the characters of Paul Bultitude (the father) and James Robertson Justice's strict headmaster Dr. Grimstone. There's also a madcap farce of a duel and a subsequent courtroom scene that's a riot.