Ken Wilson Look on Amazon.com or eBay.com and you will find used copies of Ken Wilson's Classic Rock series for anything upto £150.00. Hard Rock was first published in 1974 it was the definitive tick list of great British rock climbs and spawned a whole series including, Classic Rock, Extreme Rock and Cold Climbs (and Big Walks, Classic Walks and Wild Walks).
For the last few years Wilson has been working on a brand new edition of Classic Rock, completely revised. It was slated for publication before Christmas. Ken told UKClimbing.com,
" Classic Rock will not be out before Christmas I regret to say. It is proving far more arduous than I expected....or maybe I am just getting older and slower. I hope that climbers will consider it worth the wait, but, as you probably know, there is no guarantee of success in publishing. I would be grateful if we could discuss this after Christmas as I would like to be sure of my schedules before making any further public pronouncements."
If you want to whet your appetite for all things Classic Rock there are at least a couple of websites worth visiting.
If you go to Bob Wightman's website he has list of the climbs in Classic, Hard and Extreme Rock with those routes that Bob has done marked.
Also check out Stephen Reid's Hard Rock pages here.