"It makes me wonder if you may have a Raleigh Super Course or Gran Sport, or a Carlton that was sent back for respray, and possibly also dropout replacement and also possibly a re-badging. The bike does bear the hallmarks of a Worksop built machine, and since it doesn't have a 27.2 seatpost - it would appear to not be one of the premium models. Hoping someone else can help get to a more specific answer."
Did you notice the Raleigh headplate?
Have seen other Gran Sports with the Zeus Gran Sport ends but do not know their years.