I've had my best luck with ugly ol' knots like that if I can get 'em closer to the center of the limb. And that's center of the measurement from tip to fadeout and center of the two edges.
When the sun is low on the horizon, take that stave out in the fresh air and point it into the sun. Now start following the grain lines up and down the stave with a sharp pencil. Put your first line down the center of the stave and the next two about 3/4 of an inch on either side of that one. That way you can stand back and scratch your head figuring out where the bow actually lies in that chunk of wood. I think there is one in there somewheres.