The British Library has a wonderful collection of rare books on all parts of Asia, and includes the India Office Library Collection.
The Library of the School of Oriental and African Studies is, as you would expect, rich in rare Orientalia and reference books on all aspects thereof.
The Wellcome library, which is situated betweeen the British Library and SOAS has a wonderful collection of books remotely scientific or medical, and is very user friendly.
We are members of the Antiquarian Booksellers Association (ABA) and adhere to their code of conduct.