This is from a project run by National Library of Scotland's. They have already digitised a full suite of Scottish OS (and other) maps. They have a complete selection of 6" to a mile maps of England, see here for the Leeds area
http://maps.nls.uk/geo/find/#zoom=12&la ... &point=0,0
Click on the area of interest, then select the map from the RHS pop-up (for the same are there are maps published in 1894, 1909, 1933 and 1944, though be careful with the dates as the surveys were often completed some years before)
They are progressively working there way from the SE corner of England north and west with the 25" to a mile maps (which have fantastic detail)
http://maps.nls.uk/geo/find/#zoom=6&lat ... &point=0,0
As an example this is the River Thames from the Houses of Parliament downstream to the Hungerford Bridge and including the area I guess we would know as Waterloo (the waterfront business so close to the heart of the city are an age away from the modern city of London)
http://maps.nls.uk/view/103313045
Gateway to their resource is here:
http://maps.nls.uk/
Enjoy and consider it Scotland's gift to Secret Leeds
