For a long bow of dense, heavy wood like Osage, I don't recommend any wider than 1 1/4" at the fades. And I like to make the long ones slightly whip-tillered with tiny tips. Rectangular cross-section. And both limbs are equal, much easier to tiller and you can flip it over if the string lays off to the 'wrong' side.
"Hamm longbow" is not really accurate, because I sure didn't invent a long Osage flatbow. It's just what I've come to prefer for hunting or stump shooting; fast, accurate, and forgiving.
Hope this helps.
Jim