Perhaps I am late in the day answering, “What is that hanging beneath the Brigand?”. It is the entrance behind the main spar: all crew members entered and left the aircraft this way. Elsewhere, there is reference to a Brigand crash at RAF Colerne on 8th March 1956: I can provide further info about crew and cause of crash.
donbuzz. 25/02/2015

Brigand RH 831crashed short of the runway on 8th March 1956. The pilot had exercised engine superchargers whilst returning to base as was usual practice. Investigation of crashed aircraft found that the fuel isolation controls had been switched off instead of the supercharge controls. These two sets were close to each other, to the left of, and behind the pilot. On approach to landing, cause of sudden loss of engines would not have been immediately obvious to the pilot. The a/c crashed short of the runway. Pilot and nav/rad instructor were both killed: two student naval officers, sitting behind the main spar, facing aft, were able to walk safely away. donbuzz. 26/02/2015