Midget Sliding Tee This has a sliding offset that can be positioned at any angel in a plane and slide end over end. A staple of early wrenches.
The ¼ inch version was introduced in 1945. The finish about these changes. The first finish was the WWII finish. This is a Brushed Zinc and Brushed Oil finish that replaced the Nickel and Chrome finishes. Also the replacement of the 9/32 inch is likely a part of the World War II Government Simplification and Elimination Order L-216