Thanks for that @Once a WheelerNot at all sure about this but I am intrigued by the 3-pin fixing for the head badge. The only one I can think of
Dies look like Raleigh badge holes. Quite a few had those flutes seat stay caps
NB1 or WB1 at the start which is a, Raleigh / Carlton 1981 number
Is there any indication of the original frame colour?