Well - had a bit of a result today!
Having been inspired by all the talk about the Connaught Royal Mail Steamer I Phoned the British Library who, of course have a coy of every book ever published in the UK. They have the requisit volume of Russell's New System of Naval Architecture and are sending me a CD of the plates Engineman mentioned scanned at 300dpi.
This of course means that ANY drawings or material published in book or Magazine form in the UK (providing you have the reference) is available to order on-line.
A remarkable resource! and again VERY helpful staff.
Stuart