I suspect it will be a case of touring around physically looking,just a shame companies (esp.the big boys) don't put xmas hours on their online sites.Hey ho....
Must be an Asian tyre place open with a part worn just to keep you going ? all the ones in Manchester will be open as I had a similar situation on the ex girlfriends car this time last year.
Just to update in case it can be of any use in future to others, found a place just off Old Kent Road called Madtyres.Had exactly what I needed,quick and efficient (after a bit of discussion over a price 'misunderstanding'..) Ended up happy/on the road and would use again.