OK Jack - maybe the KH VIII is not correct, but I have seen paintings of recorders in which there were only 6 front holes. I'm not at home now, but I seem to remember in my collection I have a tiny 'recorder' (top of the 'acoustic range') bought some years ago before the very good music shop was screwed by an incompetent set of accountants and went into bankruptcy - sold as such, which is only 6 holes.

When I said 'diatonic' I was referring to the 6 hole models, not what masters of the instrument can get with cross fingering.