My Great Uncle died flying from Chivenor in April 1945. I can't recall exact dates but he was W/Op on 14 Squadron Wellington MkXIVs . I have the accident report card, only 2 of the crew were recovered, the others (my great uncle included) were never recovered from the sea. I believe the crew were killed by noxious fumes which entered the aircraft and some, if not all of them passed out. I'd be interested to hear how you go on!