Newcastle Brown has definitely got sweeter over the years, me old late Dad reckoned that happened when they started serving it chilled, before then it just sat in pints under the counter. I remember as a teenager in the 60s it used to be called "Journey into space" after the SF radio show (way before anyone's time on this forum I bet

) so I bet it's been reduced in strength from the old days.
According to Roger Protz it also contains syrups and sugars, and suggests the following hops: "a complex blend of Hallertau, Northdown, Northern Brewer and Target hops"
Hallertau, well that's a head spin

- Anyway I reckon pas' recipe is good, maybe add some golden syrup and a bit of sugar, and play around with some of the hops - NB and a touch of Target for bittering, and the others later in the process. I'd maybe leave out that Hallertau.
Cheers
Michael