I've recently created a google group for people interested in the history of asexuality. In my own view, the history of asexuality can usefully be divided into three categories. First, the history of asexual communities as "asexuality" is (generally) understood since the establishment of asexual communities in the past decade or so. Second, is cultural history involved leading up to the creation of such communities. Third, there are historical and cross-cultural categorizations similar to asexuality.
While I'm not limiting this group to any one of these, I expect the focus to largely be on the first of these (and a little bit of the second, especially in the years prior to the formation of [online] asexual communities). I've met a number of people participating in asexual communities who've been doing some important work in piecing together bits of the history--generally this has been for blog posts, the AVENwiki, or issues pertaining to the history of AVEN that are relevant to questions about how the site is run. The main purpose of the group is for people who spend time digging into the history, reading through old threads, websites stored in the Wayback Machine, and other sources for piecing together bits of the history.
If anyone wants to join, please email me and let me know so I can add you.