I'm not sure when or why Fairy Swordfish were first called stringbags. The walrus was known as the shagbat. This did seem to be based on its appearance and rather apt.
Flying very low just a couple of meters above the water it might not have been so easy to detect with radar although it has no obvious stealth characteristics.
I think the diagram can be interpretated in two ways. The first way is suggested in the posting.
The other interpetation is that the areas not showing damage for example the engines and the pilot position actually were hit as often as the other areas but resulted in the loss of the aircraft...
I don't think I can help much and I'm sure you already know what the German in the last photo means. My rather imperfect German translates it as "oil level measured 225 mm from the upper edge of the pipe" 225mm is nearly one inch. We look forward to seeing what you find out.
I would go for a Bristol but not the speedylittle bullet. I would go for a Bristol Fighter with a gunner to keeping his eye on whatwas happening behind but with a performance as good as contemporary German fighters. If I chose a monoplane it would be the Fokker DVIII flying razor blade which...