I have one with the strip of bamboo for a string, too, Barred Owl. I also have a set of arrows that came with it. And here's the kicker: It is in the same hand hewn wooden box with the shipping address and the military address it was shipped from. Here's the bummer: It's a military address, does not list the country of origin. The postmarks are smudged enough to not be able to read the date.
The wood on mine is very similar to yours, Dragoness, but blacker. I am tempted to string mine, but I pound my head on concrete until the temptation goes away.
Last year I did take the arrows and the bow out to Reptile Gardens to have someone from their gift shop look at it. I know, you are thinking tourist trap, and you are so wrong. World's largest reptile collection as verified by Guinness Book of World Records AND the gift shop is run by one of the world's foremost collectors of aboriginal art from Papua New Guinea. The arrows are a dead match for many arrows in his collection, both in style and materials.
I've seen several of these bows posted on here now, as well as had several people locally tell me about bows that they uncle/grandfather/etc has that look just like it. I have to wonder of the people of PNG had a thriving cottage industry making and selling bows during WWII???