Good find Geo.
I notice that the Humbrol equivalent for RAF Dark Green is still shown as No.30. This was the case for many years, and it was a very close match, and a good paint. But since the various changes of manufacturer of these paints in recent years, the shade is now nowhere near what it was, being lighter, and with a 'brighter' tone. The nearest Humbrol I've found is No.163 Dark Green (satin), but it can be inconsistent, and often gives a patchy finish.
Good chart though, and bookmarked - thanks.