Ding ! Correct !
It's Hawthorne, KHHR, also known as Jack Northrop Field. The airplanes under construction are N3PB patrol bombers destined for the Norwegian Naval Air Force.
Here's an N3PB during sea trials: (I know it's against the rules, but can anyone hazard a guess as to what "aerodrome" is featured in the picture?).
Otherwise Clint, over to you !
Cheers,
Tom