Collectible astronomy books and classics

I have started to form a small collection of collectible and classic books in astronomy. I am interested in boosting this collection. I am in the market to buy astronomy books first editions hardcover signed by author or with an interesting association. On my collect list I have Arthur Clarke, Patrick Moore, Fred Hoyle, Mary Somerville, Eddington, Hubble, Herschel, Agnes Clerke,Percival Lowell, Martin Ryle, Martin Rees, Stephen Hawking, etc If you have something that is taking up space in the attic and you want to convert to cash then do be in touch. I can pay in any major currency, and I pay shipping costs. But please note that I do not collect damaged books.

Simon
sam11@cam.ac.uk
http://www.totalastronomy.com