Maybe this is old news, but I just stumbled upon it.
English Heritage has posted a very large image of the Dering roll online. It’s very long - I don’t know if it’s the entire thing.
Here’s a direct link: http://eh.onlineculture.co.uk/deringroll/browserapp.xbap
Warning: the application it uses to view the roll takes quite a while to load and doesn’t work in every browser.
I found the thing navigating around this page:
Thank you for the link Jeremy. Wish I could open it haha! I’m a Mac. and despite my best efforts am unable to open the file. Ah such is life.