The cinema seen in the opening shot of this movie is ABC's Ritz, Edgware, the nearest ABC theatre to Elstree Studios. It has clearly been newly whitewashed for the occasion, and the poster for Escape from Fort Bravo (1953) visible on the right-hand wall dates it to July 1954 when that movie played the ABC circuit. The subsequent interiors are not of the Ritz, however. The screen and proscenium surround look like a studio model (the Ritz was an atmospheric design), while the rear stalls where the stars are sitting is a studio set.
The unusual piano that is delivered to the couple's crowded flat is in fact an antique Beale Euphonicon, a hybrid keyboard instrument with three soundboards, invented by John Steward in 1841, first manufactured by Beale in 1843 and exhibited at the Great Exhibition in London in 1851. The instrument featured in the movie would have been over 100 years old at the time of filming. Surviving examples of this rare instrument can now be found in major museum collections including the Metropolitan Museum in NYC and the Victoria & Albert Museum in London.