I picked up today a "collector's item" published by the Detective Book
Club (aka Walter Black, Roslyn, NY). It was one of their three-in-one
mystery collections, but bound in a heavy blue leather or leatherette,
with gilt ends and a ribbon marker. The three books a

- Erle Stanley Gardner, THE CASE OF THE EMPTY TIN
- Agatha Christie, EVIL UNDER THE SUN
- The Lockridges, A PINCH OF POISON

The three novels were orignally publshed in 1941, but their copyrights
are all listed as renewed in 1969, which is when I assume this book
comes from. There's a limitation page which says "Copy 142 of 170
copies."

There's nothing else in or on the book to indicate why this elaborate
production. Any ideas?