I have been asked about the availability of the book about Pentagram. The answer is that I was kindly sent a copy of the special edition, but Unit Editions are producing copies to order (https://uniteditions.com/products/pentagram-living-by-design-pre-order).
If you are interested, I strongly recommend it. It provides a great deal of information about the back history of Pentagram, how it came to be established, as well as succinct biographies of all its partners, including Alan Fletcher, Colin Forbes, Kenneth Grange and Theo Crosby, its founders. The text is by Adrian Shaughnessy, who has also published the book which is itself, as it should be, a brilliant piece of book production. Not cheap:-