Odd, the Great and Terrible Gurgle appears to have taken a dislike to this subsite. Completely de-indexed, even after sitemaps, page fixes, and individual pages sent in. (As I used to do this sort of thing for a living, not entirely clueless in that area.) Also, the archive bots seem to have developed a similar distaste -- last snapshots were in March. (Posted a few pages there this afternoon, perhaps it will whet the bots' appetite.)
Bit odd. Time was, this sort of hand-crafted content was the gold standard for search indexing. A little like realizing that you haven't left any footprints on the trail for the last mile. Might force me into mass-market authorship, just so I can be sure that a copy or two will still linger on Salvation Army thrift store shelves a century hence.