I came to the same conclusion too, by googling, but if so the first clue seems to be wrong. Confusion between Cornwell and Cornwall? Also, if Jack Cornwell is the answer then the clues seem to be so obscure and contrived as to be unguessable to be honest.
Well, there were 4 HMS
Chesters, and the Jutland one was the last. But it says "my" name as if this clue was about a person.
I suppose you could argue that
Chester was the last of the "Town" CLs of the old type, although there were many later CLs and CAs named after towns, some even "C" cruisers of later WW1. She did have 1 sister, and was different from the others in being built for a foreign country (although arguably
Melbourne,
Sydney, and
Adelaide also qualify there. She did, however, have different guns from all the others. She also had a name change, from the original
Lambros Katsonis.
It's widely reported that her gunshields were too short, which could be a design flaw, but photos taken right after the battle show them to be pretty much full-length (see attachment). I don't think that would have made much difference. And nobody mentions that several other Brit CLs, with definite full-size shields, also took appalling guncrew casualties at Jutland. Shields just didn't do much, regardless of size.
"One of 4 this day and 2 to see the next" and "2 in England, 1 at sea, 1 in Sweden". I have no idea how this fits in. There were 4 boys on
Chester's casualty list: Robert John Ashton, Albert Ernest Chowns, John Travers Cornwell, and Reginald Afred Raven. But I think all 4 of them actually died, because their names are all on memorials, and Cornwell didn't see the next day, I don't think. But Cornwell's gun and VC both are in the IMW--I've seen them.
But I'd have to agree, the guy in question is Cornwell, and the ship is
Chester. That's the best fit I can think of.