The clues point to a 1978 frame made in Nottingham. It sounds as though it would be a Professional model from your description.
John Barry Mechanicsburg, PA, USA
--- JEFFERY Pyzyk <email@example.com>
> After some excavation, the serial number looks like
> 8710682, though I'm not
> completely certain of the "1". The seatpost seems
> to be a 27.4 as a 27.2
> slides in rather easily.
> Jeff Pyzyk
> Milwaukee, WI