I am having a day out in Manchester on Friday - my first "day off" since DS was born 20 months ago! Over here on t'other side of the Pennines I have heard talk of an Office Shoes clearance shop.
My main (only?!) points of reference are Piccadilly station (where I will be arriving) and M&S. And the Corner House gallery, although I am guessing that that may not be in the right direction.