To answer a few of your questions, yes incense cedar is a light wood and quite soft. Soft to the point that when unbraced and traveling with it, the sinew string will scuff up the smooth sanded wood. As far as the decoration. I modeled them after the original I was able to inspect from the Lowie museum of anthropology in Berkley. The handles are wrapped with a thin strip of brain tanned deer hide. The bow was covered with a black stain that I think was a diluted pitch that probably somewhat watterproffed the sinew and camouflaged the bow. I wouldn't go any further than that.
The cedar was cut in the western sierras. there is allot around there.
There is one picture of the bow unbraced. It is almost flat but has a very slight bit of string follow after being shot at full draw quite a few times. Before the bows were strung after the sinew was cured they held about a 4" reflex. I am experementing with even more sinew less wood and limb bows right now to see if I can keep the reflex after shooting.
And Billy. Can you tell me where you saw these Miwok originals. I have only been able to inspect and measure 1 in Berkley. it like the photos I have seen had a rounded back and belly like a lemon cross section. I have never seen one with a flat belly, and a random cedar bow I made with one broke. California Nutmeg was the other preferred wood. Thanks for the info on the string to. I saw a photo of a bow that had a brain tanned wrapped handle and looked like it had it on the re-curve to, but on close inspection it was a sinew wrap, I do this to keep the sinew from pulling up when drying