The Public Life of Sherlock Holmes: The Final Adventures of Sherlock Holmes (Haining)
Peter Haining was a notable Sherlockian who compiled/edited several useful Sherlock Holmes books.
Back around 2005 or so, an article in the Wall Street Journal was about Barnes & Noble’s in-house publishing imprint. They have been reproducing classic works for years and selling them at affordable prices. But they range father afield than that, and my Sherlockian bookshelf includes several of their titles, such as The Sherlock Holmes Companion, The Lost Adventures of Sherlock Holmes and The Final Adventures of Sherlock Holmes.
The latter was the main source for the Doyle on Holmes series. The Final Adventures of Sherlock Holmes is a collection of stories, plays, and essays about Holmes that are not part of the Canon but certainly make nice supplementary reading. An excellent addition to any Holmes library.
It is somewhat similar to the out-of-print and often difficult to find Sherlock Holmes: The Published Apocrypha by Jack Tracy. Both books include the “almost Sherlock Holmes” stories and plays that don’t fit in the Canon, but are certainly in the neighborhood. I wrote about that one, here.