I don't really understand the confusion some reviewers seem to have with the title. This book has always been called 'Coroner's Pidgin' in the UK, and 'Pearls before Swine' in the USA.
It is unusual in that it is the only wartime novel I have read that takes place after it had become obvious that the war in Europe is won, but some time before Hitler committed suicide. Probably most authors thought this a rather dull period! Not so Allingham who presents an excellent and gripping mystery about a Nazi plot, initiated before war broke out, to ensure that valuable art works were safely out of bombing zones so that they could be carried off to the Fatherland after the invasion of Britain. The British organiser of the necessary thefts and murders remains a mystery almost to the end of the novel.
In customary Allingham style, the ethos of London in the period is brilliantly portrayed and Lugg has a couple of wonderful, if unlikely, cameos. Once as the accomplice of a titled lady who is attempting to hide a body, and even more exotic, as Lugg the warden, keeping a pig in one of London's most fashionable squares. There is the usual crop of nutty characters, probably the best of which is Miss Pork, an upper middle-class rural lady with a secret she doesn't know she has. (Allingham has a subtle flair for names that rivals Dickens at times)