Very nice work. I'm sure the bows aren't meant to be pulled past a string angle of 90 degrees. Your first full-draw looks about 90, the second is going past. Native Americans drew to the chest didn't they? In addition to possibly being generally of smaller stature?
And I can see how it would be tough to shoot them accurately since the reflexed handle is putting your hand behind the arc of the limbs, amplifying any amount of torque in your grip. You run into that some with modern bows that have a reflexed riser.
Fine job on the sinew. Did the bows pull into much reflex when it dried? I suppose you heat-bent the bows to shape, then sinewed? And I may have missed it, but what example were you copying on that second one?