Love watching this project develop! I have to mention though (and I'm not sure how far you're striving for realism here) but the way this bow is strung here wouldn't work. Once the bowman sets the string, it is pulling the ends against their natural inclination and therefore has to lie down from the tips against the opposite side of the shaft, like in this http://classic-bow.com/catalog/images/0245_recurve_bow.jpg. The way its strung in your picture the bow would simply snap back to normal. In the vanilla version the string just kind disappears without detail so it gets away with it. Here's another http://wiki.robotz.com/images/d/d7/RecurveBow01.png.
As someone who shot a bow a lot as a kid, I couldn't help pointing that out. Carry on.