I'm sure someone else will give you a more accurate answer. But at least this is a start: You've confused two episodes. Twain and Howells did indeed get all messed up trying to reach some ceremonial occasion outside Boston--a source of frustration at the time, but later something they laughed about. But the episode with the sealskin coat came several years earlier, and the offended lady was Mrs. Thomas Bailey Aldrich. I'm nearly sure both stories are in Justin Kaplan's biography. If Kaplan doesn't include a picture of the sealskin coat, you can find one on p. 115 of the old picture biography MARK TWAIN HIMSELF, by Milton Meltzer. Mark Coburn