Though the term “flageolet” appears to be applicable to duct/fipple flutes in general, I recently dug into some online reading about the specific type known as the “English flageolet”. I’d seen these in museums, and in their “double flageolet” format, but was intrigued by an earlier mention on C&F that the “barrel and beak” construction of later English flageolets softened the tone and smoothed out the air pressure, similar to what we see in the dual-chamber system of the modern Native American flute.
Note in this image how much chamber there is before you even get to the air window:

Here’s a not great clip of one on YouTube: http://www.youtube.com/watch?v=98aB56-1OeI&feature=results_video&playnext=1&list=PL31EAA8F070BE24BA
And a clip of a double-flageolet: http://www.youtube.com/watch?v=0MLeySdZILc&feature=autoplay&list=PL31EAA8F070BE24BA&playnext=2

I know there are plenty of folks making wooden “tin” whistles that would basically be equivalent to earlier English flageolets, but is there anyone currently making whistles that have a chamber prior to the fipple? It’s an interesting-looking design, and I’m curious as to how it would play.
Any insight as to any contemporary experimentation with this sort of design?