Designed by Dick Hess 1980;
this puzzle made by J. A. Storer 2007
from a 1961 Adams Co. Dad's Puzzle and two plexiglass L-shaped pieces.
(cardboard sleeve, metal tray, and 8 plastic / plexiglass pieces, 3.75" x 3" x 5/16")

Hordern's book presents the following solution of 28 rectilinear moves (corresponding to 33 straight-line moves). Shown below are each of the moves where an L piece moves. The basic idea is to swap the 1x1 piece with the piece below it and then from Step 10 move the 1x1 piece to the lower right corner (Step 14) before trying to bring the L's together. Note that the only other possible final position can be achieved by modifying this lower right solution to have step 28 move an L up rather than down.