Petrusja
The northern airport / Karachi Civil airport was a pre-war airport - would have existed from the 30s. Its the airfield where they built the Air Ship Hangar and tower for R101 and also housed the Karachi Aero Club. (Eg.. see if this image opens-
https://scontent.fphl2-4.fna.fbcdn.n...bd&oe=5ECCB1AC - this is Karachi Civil )
It is the one that would have been used by the Civil airlines in the 30s