240,
With a "stave bow" there can be so many different variables that could cause thickness differences in a tillered bow...Knots, ring thickness, grain, etc...I have never had two limbs exactly the same thickness after final tiller...I think we have all been to a point where we say why isn't that limb moving because it looks thinner in that spot...The way I see it, if it's bending, I move on to the stiff area whether its thicker or not, the wood is telling me it's bending here...With your Sassafras, I would suggest using as much of the limb as possible to relieve stress, no long stiff tips...Just my HMO...
Don