Not to worry, though, as I already completely developed a method to get exactly what I'm after, and (you must've missed where I) already posted it: my "Extracted-Bead" Method. Although it's quite a bit of work (believe me, I'd love to be able just to draw these on, feathered!), it's highly effective - and quite flexible for doing any feathered shape(s), thick or thin.
You may recognize this specific camo scheme, Donny: it's on (a Ju87 Stuka on) the cover of the Guide to Airbrushing book you sent me - which just arrived yesterday! I already skimmed the article, and they do indeed admit that it's very difficult - even with an airbrush (which I don't even have) - plus I think their pattern still looks a bit too "close-packed", and mine is going to look better, anyway! So, stay tuned for that.
And again, Thanks for the info on the paint pens, Don!