Dredging up this thread to provide new information.
The one the OP was looking at--and we don't know whether he
got it--is most likely part of a United States Navy contract. Mine
like it is s/n 707084, and it shipped on March 5, 1969, to Crane,
Indiana.
Crane is the home of Naval Sea Systems Command, which it
appears was started in 1941.
The Airweight does indeed have the lanyard mount drilled
through the butt's serial number, and it has the number
stamped on the frame in the yoke cut in the same style as the
late '70s Navy contract overruns.
Have to keep looking under the rocks. Never know what might
turn up.