Toby, thank you very much for our thoughtful answer. I spent many years as a dealer in antiquarian books (pre-1650) and maps. I used the auction houses to dispose of the dogs that eventually found their way into my inventory. Nothing unethical about that - I couldn't sell them but someone else wanted them. It is a common fallacy made by many people that auctions are the place to get bargains. Yes, they sometimes show up, and every once in a great while something escapes the notice of every dealer and expert who has pawed over the lots.

Anyway, thank you again for your response and I may get in touch with you privately regarding my desiderata. I get to London about twice a year but never when the gun sales are on!