Page 471: The official record of the charges and sentences can be seen on this Sources page. The document is held in what is now called Cheshire Archives. An additional point is that Arnold Murray was defended by Mr Emlyn Hooson, later Lord Hooson.
Page 502: At the suggestion of Paul Greengrass, I included in the Preface to the 1992 Vintage edition a suggestion that AMT might specifically have have been consulted about the Anglo-American Venona project. This involved the post-war decryption of highly sensitive Soviet messages.
Pages 512-4: I took Turing's last postcards very seriously and gave this super-long footnote. It contained a hint about the later role of Roger Penrose in developing the geometry of light rays. In 1983 I did not know that Penrose was to make a much more direct link with Turing's ideas in his discussion of computability and its relationship to the physical world. (See The Emperor's New Mind and Shadows of the Mind.) In particular, Penrose's theory is that wave-function reduction must involve an uncomputable operation. I have written a short piece for the last volume of the Turing Collected Works which expands on these remarks; this is available on this site.
There is further material in the Alan Turing Internet Scrapbook: Wondrous Light.