I recommend a book entitled Heathrow 2000 Years of History, by Philip Sherwood. First published in 1999 my copy is from the 2001 reprint. It is on Sutton Publishing and the ISBN is 0-7509-2132-3. The book contains many interesting photographs and maps, especially those in chapter eight. It is also vey thought provoking as to how the place has changed even since this book was published.
re the previous posts in this thread, thanks for the excellent pictures. I have only been at Heathrow since 1979 so am still really a newbie.