hi paul, sorry i came back here too late to post about other bookstores in london - you’ve been and gone. there’s one that you get on the black tube line going north a few stops from the centre, to Old Kentish Town (or something Lord-of-the-Rings-sounding like that), called the Hellenic Bookservice. They had tons of classics books – you know, the type of bookstore that has a pretty full range of loebs and OCTs and the Cambridge Latin Course and dictionaries and things like that, as well as a few commentaries and linguistic studies, including lots of second-hand books as well as modern. nearer to the centre, I used to go to a big modern store called foyles or something on Charing Cross Road, it’s in the same general area as the british museum and not far from the eurostar. They have a full classics section of modern printed books a few floors up, as well as a second-hand section even further up from memory.
the second-hand sections in bookstores and bookmarkets in europe are always great because it seems generations of people have dumped books which they can’t read from their grandparents’ bookshelves into the market. their loss is our gain. cheers, chad