Thank you to Peteg for posting this link, I managed to print of a hard copy.
I haven't digested it all yet but was interested to read the introduction to the Silbury section is written by David Field who is the author of a book I am currently reading called EARTHEN LONG BARROWS (the earliest monuments in the British Isles). It says on the back that he has spent 15 years as an Archaeological Investigator working with English Heritage and specialising in Neolithic and Bronze Age landscapes.