Dorothy Sayers, of course, is the author of the Lord Peter Wimsey books. I love these; I read them as historical novels as much as as mysteries (mid-1930s England). Did I mention I'm an anglophile? (I come by it honestly, my father was born there.)
The Nine Tailors : Changes Rung on an Old Theme in Two Short
Touches and Two Full Peals
Busman's Honeymoon : A Love Story With Detective Interruptions
Lord Peter goes undercover in an advertising agency to solve a murder. The author worked in an advertising agency at one time, and I wouldn't wonder if the details are right. There's a lovely discussion of the important distinctions between being made "of" something, "from" it, and "with" it. This is also the book where Lord Peter does his very surreal harlequin character in the evenings.
I've written notes on the books I read for a while now, including a number by Sayers.
See them all here .