The North/South of England thing reminds me of a folk music debate
which has raged in the New York area.

When William Main Doerflinger got 'The Leaving of Liverpool' from
Dick Maitland, he got the final line of the chorus as 'But me
darling when I think on you.'

A faithful collector, Bill recorded it exactly as he had it from
the source. Maitland, in turn, claimed to have heard it through the
open porthole of a f'oc's'le.

A number of us asked Bill about it over the years, and his explanation
was always that that was the way he collected it, so that's the way
he published it.

Anyway, many performers have fixed the song so it rhymes--- "...when
I return united we will be. It's not the leaving of Liverpool that
grieves me, but my darling when I think on thee." Some of the
New York area 'purists' have been pretty adamant that it's 'you' and
not 'thee' citing that 'thee' is an ancient usage that never
would have been in vogue at the time the song came about (and we
can date it fairly positively by other references).

At this, as the grand-progeny of a gen-u-ine Lancashire family
which emigrated to California in the 1920's and whom I remember
quite well, I always chuckle derisively. For they've obviously
never heard the speech of a Lancashire (or Yorkshire) native
born between 1895 and 1905. If they'd heard my grandparents or
my aunts and uncles talk amongst themselves, they'd be singing
a different lyric! They might not have been saying 'thee' in
London when the Davy Crockett was plying the seas, but they
sure as heck were in Manchester--- and, one supposes, over in
the 'Pool.