Patented E. Johnson 1940, David Co. circa 1990's?, lower right circa 1960's?.
(top: 3.5"x2.7"x1.4" box, two 3" wood pieces, and directions;
lower right: 2.5"x1.75"x1/2" plastic box and two plastic pieces)

Further Reading
Johnson Patent, from: www.uspto.gov - patent no. 2,216,915