The aircraft seen in the opening credit sequence, BOAC Boeing Stratocruiser G-ALSA, was involved in the Prestwick Air Disaster in 1954, killing 28 of the 36 on board.
Peter Jones had his voice dubbed for some reason.
The scene where 'Jimmy' the safe cracker opens the safe shows 'Robert' and 'Barbara' wearing gloves throughout, presumably to avoid leaving finger prints whilst 'Jimmy' the well known thief takes his gloves off to crack the safe and goes on to handle other objects, leaving his finger prints.
Opening credits: All the characters and incidents depicted in this film are wholly fictitious and any resemblance to any firm, institution or persons alive or dead is coincidental.