According to my references on the Beaufighter the original concept is described as:
"As Bristol prepared to test flight the first Beaufort, chief designer Leslie Frise and his colleague Roy Fadden, undertook a design study of the new torpedo bomber to see where the airframe could be adopted into a stop-gap fighter. The RAF would, it was estimated, be critically short of fighters in the event of war.
The idea of producing a fighter with minimum cost and without the long timescale needed for an entirely new, off the drawing board, aircraft was enthusiastically taken up by the Air Ministry Staff. A few days after the first Beaufort flew, Bristol was asked to build four prototypes of the Beaufort Fighter."
Scott (espins1), the Beaufighter I'm doing is the TFX Beaufighter UB-E (pictured below) from 455 Sqdn RAAF which was attached to RAF Coastal Command. The color scheme is extra dark sea grey over sky with invasion stripes.
Cheers