Thinking Avro Anson or Bristol Beaufighter.
But roundel on Anson was closer to wing tip.
So with the clue of "first flew in 1939" I will go with the Bristol Beaufighter which first flew on July 17, 1939. The Anson flew earlier as a civilian transport prior to the war.
And the BFs roundels were positioned closer inboard on the wings.
Bristol Beaufighter