I used to recommend I & J Macdonald in Lanchester , but they closed and the business was taken over by Beamish Morgans. Within the last year/s or so their chief mechanic (ex Macdonald) has set up on his own.
I don't have his details but I am sure that there are others here who do , his name is Peter Davison. Not sure if he has a rolling road any more.
Outside of that, and I know it is a bit outside your NE area, the only outfit I would recommend is Mark Adams near Shrewsbury (who designed the Tornado chip) for the 14CUX.
https://www.tornadosystems.com. He is the absolute authority on these engines and will get the very best he can from yours.
You could do a lot worse than just purchase a Tornado fuel chip for the 14CUX ecu and fit it yourself.
From experience the chip works best when you have a free flowing exhaust manifold, (Librands or similar) and a less restricted air filter than the standard black cannister.
