The Blurb for A Louse for the Hangman

From page 1 of the first (and only) edition of A Louse for the Hangman by Leo Bruce, published by Peter Davies (London, 1958):
Mr Gorringer, headmaster of the highly-respected Queen’s School, Newminster, disapproved of the publicity brought to his school by the extra-curricular activities of its amateur-detective history master, Carolus Deene.  But when Lord Penge, a friend of long standing and a very rich one too, started to receive threatening letters, the headmaster decided to make an exception, and asked Carolus to investigate.  The letters threatened death to Lord Penge, but it was Michael Ratchett, his secretary, who was found shot in the park of the Penges’ luxurious house, Highearth [sic*] Manor, Ratchett was found to be wearing Lord Penge’s overcoat—had the murderer made a mistake and shot the wrong man?
From the front flap of the dust jacket of the same edition:
Mr Gorringer, headmaster of the highly-respected Queen’s School, Newminster, disapproved of the publicity brought to his school by the extra-curricular activities of its detective-cum-history master, Carolus Deene.  But when Lord Penge, the Meat Paste King, a friend of long standing and a very rich one too, started to receive threatening letters, the headmaster decided to make an exception, and asked Carolus to investigate.  The letters threatened death to Lord Penge, but it was Michael Ratchett, his secretary, who was found shot in the park of the Penges’ luxurious house, Highearth [sic] Manor, Ratchett was found to be wearing Lord Penge’s overcoat—had the murderer made a mistake and shot the wrong man?
Inevitably, Carolus found that practically everyone connected with the household could have committed the crime:  and motives abounded, assuming that the killer had made a mistake.  When mysterious faces were seen looking through the Manor windows, and Lord Penge’s medicine was found to be poisoned, tension increased, and Carolus warned Lord Penge that he would be in grave danger if he left the house.  But next morning Lord Penge was found shot, in the garage, and Piggott, the footman, was arrested and charged; and the police were satisfied.
It was left to Carolus to explain to everyone what had happened:  but it was a solution that frankly revolted him, as well as shocking Mr Gorringer.
*  Lord Penge’s country residence is Highcastle Manor.