While I am waiting for my B to be built I took the opportunity to ingest some of the history and culture of the Brompton by checking out this book by David Henshaw. This is the second edition of the book and it was released in late 2011, so it is pretty much up-to-date.
About 2/3 of the book provides background and insight not only about the company, but also folding bikes in general. There was much discussion about the Bickerton and Dahon folding bikes and their impact on the folding bike scene as well as the company. Andrew Ritchie (the Brompton designer) is painted not only as an engineer with a relentless pursuit of perfection, but also a a shrewd businessman, particularly in the early days. The book follows the company from its inception through all of it's trials and tribulations, such as it's inability to find a company to take on manufacturing early on, to the headache of the company's licensing of the bike to the Far East and the near crippling demise of Sturmey-Archer (supplier of multi-gear hubs). In addition to Ritchie (who seems to have quite a bit in common as one Steve Jobs), there were many other people highlighted in the book, such as timely investors, designers and competitors.
There are a few pages on modified Brommies... recumbents, ultralights, tandems, electrics, etc. The rest of the book is kind of an owner's manual, although without the step-by-step detail. It is very handy in detailing the tools needed to do maintenence, calling out parts that need occasional lubrication, and common problems. This is also very handy if you are looking at buying a used, older Brompton as it will point out problem areas that you should check out.
This book should definitely be in the collection of any Brompton owner. It is a great reference, especially to new owners like me. I believe that it may only be published in England, however I was able to get my copy used through Amazon.