Hi Darius.
The ship was sunk by three Beauforts of 42 Squadron, flying from Wick. During the battle, two of them, L9813 and N1159, were shot down by Bf-109s of 4./JG 77 (at 18:30?). From your post I learned that the British attacked with bombs, not torpedoes. I myself would like to know how many ships were in the convoy.
https://forum.rafcommands.com/forum/...ure#post193290
Sergey