I suspect that there is a lot of material in archives that would fill many gaps, it just requires someone to do the research and publish. There will certainly be a lot of interesting stuff with the Kingston Aviation group, www.kingstonaviation.org, and probably at Brooklands, www.brooklandsmuseum.com, so someone who is a member would probably be in the best position to do so. The pdf file linked in the topic here http://www.secretprojects.co.uk/forum/index.php/topic,22921.msg232688.html#msg232688
shows some of what is available.
The Hawker Aircraft Putnam volume is now very dated so the market is open for a replacement, and magazines such as The Aviation Historian would no doubt be interested in specific topics.