In July 2007 I went to the Museum of Natural Sciences in Bergamo, northern Italy, to look at two of the oldest positively-dated Lakota flutes. They were 'collected' by an eccentric Italian - Count Beltrami - who set out to find the source of the Mississippi. In 1823 he met a band of Lakota Indians - described as Santee Sioux - and sent two flutes back to Italy. One of them is pictured alongside - it's made from a single piece of Western Red Cedar, just over 26 inches long overall. The museum thought it was incomplete but I persuaded them otherwise and they asked me to play it - for the first time in over 180 years.
I now make many of my flutes using an open mouthpiece and tiny block based on this 'Beltrami flute'; they are very easy to play, are very controllable, and I find their visual simplicity very appealing. The lower picture alongside is an example of one of my 'Beltrami' flutes. I haven't attempted the 'fish-face' end of the historical flute, as I don't know anything about the imagery involved.
