As has been recently noted, Platt and Munk reprinted a number of the very popular Altemus’ Wee Books for Wee Folks titles. http://henryaltemus.com/reprints/platt.html

By 1938 some of these titles were sold in four book boxed sets. Starting in 1942 the boxed sets contained 3 books.

Here is an example of a three book boxed set. It cost $1.05.

It is #650g and contains:
The Story of Chicken Little
Three Little Kittens Who Lost Their Mittens
The Old Time Story of the Three Bears