Remake of the 1950 film Blackout.
Gordon Jackson and Sir Michael Caine appeared in The Ipcress File (1965).
Arthur Lowe and John Le Mesurier appeared on Dad's Army (1968).
The name of the smugglers' flying company was "Mid-Century", which was also the name of producers Robert S. Baker and Monty Berman's production company on some of their movies.