Omnibus of Crime edited by Dorothy L. Sayers
First edition, the Deluxe edition with slipcase. I had been looking for a first edition for many years, because it contains a story by Ernest Bramah. I purchased this copy for a few dollars, later to discover that the front of the dust jacket had been signed by Christopher Morley. He did not contribute to the book, but was quoted in a blurb on the slipcase. This book is rare to find with the dust jacket; the front flap says at the top "tear this off and use as a bookmark." Luckily the owner of this copy ignored that advice.