This is the site for the photo galleries of the London & North Western Railway Society. The society's home page is here: http://www.lnwrs.org.uk
Images are scanned at 300dpi and are 2700px wide which will therefore give satisfactory 9in wide prints, subject to the quality of the original. The quality of the original may be found by following the link to the LNWRS Photo Catalogue, where further details of the photograph can also be found.
Most Galleries contain Classes of LNWR engines, however many have their location in the title. Searching for locations and keywords (such as troughs, station, Clerestory) will give a set of results of engine photographs at a particular location. Expect location specific galleries to be included later.