The otherwise excellent 'unabridged' audio edition (read by Ian Carmichael, who portrayed Lord Peter in most of the adaptations of Sayers' novels) actually omitted 3 of these 12 stories, although the rest were indeed unabridged.
The complete set of short stories can only be found in the _Lord Peter_ collection; apart from that, this volume is the largest single batch. They don't overlap with _Hangman's Holiday_ or _In the Teeth of the Evidence_, which contain both Wimsey and non-Wimsey stories.
"The Abominable History of the Man with Copper Fingers" - Varden, an American actor and a guest of one of Lord Peter's friends at the Egotists' Club, tells a story of an encounter with a mysterious stranger years before. A good story; Sayers' rare American characters are much better than, e.g. Christie's, although Varden does slip occasionally into British colloquialisms.
"The Entertaining Episode of the Article in Question" - Omitted from the 'unabridged' audio edition, Heaven only knows why. The affair of the Attenbury diamonds, so often mentioned elsewhere as the beginning of Lord Peter's career in detection. A word of warning - Sayers never provided English translations of French dialogue unless forced to do so by her publishers, so part of one scene may be incomprehensible to the reader.
"The Fascinating Problem of Uncle Meleager's Will" - "A woman who pretends to be serious is wasting her time and spoiling her appearance. I consider that you have wasted your time to a really shocking extent. Accordingly, I intend to conceal this will, and that in such a manner that you will certainly never find it unless by the exercise of a sustained frivolity." This letter threw down a gauntlet for Hannah Marryat, one of Lady Mary's terribly earnest Radical friends (who will otherwise lose the money to the Primrose League via an earlier will). Very enjoyable; a shame it wasn't included in the audio edition (it involves a visual clue).
"The Fantastic Horror of the Cat in the Bag" - One motorcyclist chases another all along the Great North Road, followed by Lord Peter's Daimler, in pursuit of a small bag. But instead of the Dowager's jewelry stolen from Lord Peter in Piccadilly, the bag contains a woman's severed head. Which of the denials of ownership is a lie?
"The Unprincipled Affair of the Practical Joker" - Mrs. Ruyslander is the victim of the bald-faced theft of two items: the 'Light of Africa' (a diamond necklace of 115 stones), and a small portrait 'with an inscription that nothing, *nothing*, could ever explain away.' Lord Peter tackles the job of retrieving them from the thief without exposing Mrs. Ruyslander's secret.
"The Undignified Melodrama of the Bone of Contention" - ENORMOUS, for a 'short' story, and not really worth the trip. Lord Peter's hosts are on the stuffy (and in one instance, spiteful) side, and gossipy, which gives us the background on the local rich old reprobate whose funeral is on the morrow. The mystery here isn't about the death, but who steals the body, and why. Sayers throws in a good bit of supposedly supernatural hocus-pocus for trimming. Although the old man's sons are named Martin and Haviland, they're not related to the 'Haviland Martin' in _Have His Carcase_. (This one *wasn't* cut from the audio edition; I'd have traded it gladly for the 3 that were, visual clues notwithstanding.)
"The Vindictive Story of the Footsteps That Ran" - On a hot June day in 1921, Lord Peter and Bunter have called at the home of a medical friend, a Bloomsbury G.P. who appreciates Bunter's photography of his experiments. Throughout their conversation and the meal, Lord Peter notices the footsteps of the doctor's neighbours on the floor overhead - which end in murder.
"The Bibulous Business of a Matter of Taste" - One of Lord Peter's government errands, for the War Office this time; he is to purchase a formula for poison gas. Some bright person sold out, however; two Lord Peters show up at the scientist's country estate in France (as a titled Royalist, he offers no allegiance to the upstart French government). The story follows Death Bredon, a 3rd party carrying a letter of introduction. Le comte proposes to find the real Lord Peter with an impromptu wine-tasting competition.
"The Learned Adventure of the Dragon's Head" - Introducing St. George, staying with his uncle Peter during an outbreak of measles at prep school, as well as Lord Peter's first meeting with Bill Rumm. St. George buys a damaged rare book (nearly all the double-page maps having been torn out) which the bookseller picked up at an estate sale. The audio edition omitted this story, probably because the "treasure map" on which the story turns is a visual clue.
"The Piscatorial Farce of the Stolen Stomach" - 95-year-old Great-Uncle Joseph left medical student Thomas Macpherson only one thing - his digestive system in a bottle - before jumping out a 6th-storey window after a stroke. "He left a letter. Said he had never been ill in his life and wasn't going to begin now." Lord Peter takes an interest after Mac (a fishing buddy) mentions that cousin Robert, the residuary legatee, can't find most of the old man's assets. You really should listen to Carmichael's narration of this one. :)
"The Unsolved Puzzle of the Man with No Face" - A strangler left the corpse on the beach at East Felpham, face mutilated beyond recognition. The story begins with several strangers on a train discussing the newspaper headlines - one of whom turns out to be Lord Peter, and another the inspector in charge of the case.
"The Adventurous Exploit of the Cave of Ali Baba" - Begins with a newspaper account of Lord Peter's will, mentioning his death at age 37 in a hunting accident in Tanganyika. Rogers, upon reading the story, breathes a sigh of relief and proceeds with his plans to join a criminal mastermind's burglary & blackmail organization. The story follows Rogers, rather than the efforts of the Law.