If its anything like a will I ordered from the University library some while ago it should be pretty straightforward.
Click the website link on Coquet's message and have a look for a map, there are some in the Grey papers. There is a link to the side of the page called Document Delivery Service. If the map has a ConneXions link you can order it through the DDS. Just cough up some money
Just had a look, I think you'd have to give them a call about getting a copy....can't see any links to ConneXions.