My main aim was just to measure them and get some general pics of their appearance - I can't really read the writing and my Latin sucks balls anyway. But it was just a cool trip, and it was cool to see the real version of the translated book I've been using for the essay. By the way the essay is about the royal forest of Northamptonshire in 1255, and law cases relating to deer poaching ('pleas of the venison') which were heard by the travelling forest judges every 7 years.
Here are some pics of the mission:
National Archives:

The plea roll tied up in protective green thing:

The roll, before... unrolling. It's pretty small as you can see:

Unrolled:

An example of a case summary:

I also had a brief look in the Pipe Roll for 1255, which is a much more extensive record of the king's yearly income. It was much bigger with better writing, but I couldn't really make any use of it; still a cool object though:


Anyway, total nerd feast, but it was exciting and quite humbling to handle documents penned 750 years ago, which have sat on various shelves since the Middle Ages!