Moving Day

a.k.a. a.k.a. 5-Block Puzzle, Lodging House Difficulty
Very old design, this one made by J. A. Storer 2007.
(cardboard sleeve, 5 by 7 by 3/4 inch wood tray, and five wood pieces)

The problem is to exchange pieces A and B by sliding the pieces::



Presented in the 1914 Loyd book; both the 1942 Filipiak book and the Hordern book present a 17 moves solution (and Baxter's Page lets you play it on-line):



Further Reading
Baxter's Page, from: http://www.johnrausch.com/SlidingBlockPuzzles/classic.htm