Mechanics is the Mechanics’ Tool &Forge Company founded in 1938 in Sabina, Ohio.
Allied is Mac Allied Tools founded in 1945 in Akron, Ohio.
Clinton is the Clinton Tool Company founded in 1944 to manufacture sockets and drive tools.
This wrench has the design invented by Charles W. Bowers with the patent number 3,466,956 filed on Dec 4th, 1967.
*** MAC --- ca. 1960s - 1970s ***