There is an excellent Local History section at Warrington Public Library (they are on the web I believe) which I have used (there are numerous historical links between Warrington & the Island ranging from Bishop Wilson's wife (Pattern family) to the Dumbells - they probably have a history + many photos of the works. The tannery I think you may be referring to was still in operation until possibly 20 years ago - now demolished with stores on the site - it backed onto a bend in the river near Bridge Foot