IO: "The UK midair stats, post-WW2, are 100% in VMC and nearly all below 1000ft." Not strictly true, if you meant to include gliding incidents in that generalisation, although the exceptions do not alter the general thrust of your argument.
I have gliding collision statistics since 1987, and powered aircraft statistics for a recent ten-year period, and know the circumstances of some of each. A lot of the information, however, is not in the public domain.
I also have Airprox data covering a 22 year period. These inevitably are underreported, particularly like-on-like at the low end - e.g., there are no glider on glider or paraglider on paraglider Airprox reports, though I know that there are incidents that fall in the former category and expect there will be in the latter - but we don't report on each other when flying the same sort of thing.
It is certainly true that there is a preponderance of incidents within the circuit area and at heights not dissimilar from circuit heights - that is where most flying things mostly come into proximity.
I think I have been corresponding with your alter ego recently, by e-mail. If that is so, I have an e-mail address for you, and can send you some information privately, if you are interested.
Chris N