Holiday Camp and Boys in Brown, both acute social histories in different ways (though the first does what it says on the label and the second is about borstal, so there is overlap), also merit attention. And there is Gainsborough’s entire Will Hay catalogue, before he went off to Ealing, with gems such as Oh, Mr Porter! and Convict 99.

Studio Canal have restored most of the best-known Ealing films for Blu-ray, but some of the best are not the best known: The Magnet, Lease of Life (in colour, shot on location in Lincolnshire, with a superb performance by Robert Donat) and Hay’s best film, My Learned Friend.

Most great British films from the 1930s await restoration: the superb adaptations of Shaw’s Pygmalion and Major Barbara, but also The Scarlet Pimpernel, Fire over England and The Private Life of Henry VIII. Two of John Mills’s finest – The Long Memory, directed by Robert Hamer, and The October Man – are hard to find even on regular DVD; as are the 1955 film of Terence Rattigan’s The Deep Blue Sea, which I think has never been on disc, and the captivating 1950 social drama Chance of a Lifetime, about a conflict been workers and bosses at a tractor factory, which only turns up in boxed sets.

Some Powell and Pressburger films have been restored, but four of their works of genius have not: 49th Parallel, I Know Where I’m Going, The Small Back Room and a film that I believe is among the greatest handful of English films ever made. When the great restoration project begins, it must begin with A Canterbury Tale, which, scrubbed up, would be an absolute revelation.