First, I'm not sure where you would use an electric impact gun for woodworking. Then, why would the author use a sixties design rendering as an illustration for what was a fairly common tool?
However, I did learn what you call that square thingy you stick the sockets onto...
Also after Googling Mall electric impact, I also discovered that Mall was a real tool company and that this impact gun actually exists.
The Mall Tool company was started in 1921 by Arthur Mall of Milwaukee. He soon moved the company to Chicago and was quite successful making and selling power tools of all types. For a more comprehesive post on the Mall Tool company see the Duke's 2012 post here. More history here at Vintagemachinery.org