I think there has been something of an informal conspiracy of silence about the contents of the Castle & Crusade Society's famous 1970-1972 fanzine Domesday Book over the years. I suspect this has been driven by a perfectly natural tendency on the part of collectors to create a mystique about rarities in their possession - though really, I'm not pointing fingers here, and even if I were, I'd probably have to start by pointing at myself. People are also starting to get serious about the history of D&D, however, and this secrecy really is doing the historical community a disservice. I think we need to shatter a few myths and shed a bit of light here. I spent the better part of five years trying to assemble enough evidence to be able to say what really happened in the early history of role-playing games, and it was a near-constant process of discovering that widely-held beliefs are inconsistent with documentary evidence.
So, to kick off with some heresy, I don't think the Domesday Book is very important as a historical resource.