Rich- I just see if they are starting to bend while floor tillering. After that, I either start with a tilering device or using a low brace height and checking the balance there. Generally, if you can string it at 4", it should be bending enough. As for shape, a rectangular or semi rounded shape works for the limbs. 1 1/2" wide at the middle 4-8", tapering to 3/4" tips (you'll be lightening these later for better cast). Thickness: the handle should be somewhere around 3/4". At 76#, Sweety is 7/8", as is this bow. Taper the thickness about 1/4" to the tips (Leaving a little build-up of wood in the thickness of the handle should yeild a more elliptical tiller.)
Oldbow- Now THAT is an idea
!!!!