Aircraft Navigational Computer Type N

This is a WWII-era Aircraft Navigational Computer Type N.  

The bottom of the metal case contains a mechanical computer to solve the wind problem. It has a locking mechanism and a movable arm for drift, adjusted for air speed, interconnected to the heading tracker. The lid contains a calculator for speed, time, and distance, and gals/.  

The carton measures ~ 11.5 in x 4.5 in x 1 in. Its is in very good condition given its age.