it so hjappens that I'm working on my first White Ash flatbow Bob, after 5 years and a bunch of other woods and styles. Mine is set up at 69" nock to nock, 7" between fades in the handle area, 1 7/8" wide from fade to mid limb, then stepped tapers at 8" and 4" from tips to 1/2" wide. I'll tiller it like that and then slim down down tips. I'll probably heat in a little reflex over a stove burner with a little oil rubbed on, stringing it hackwards and tightening gradually. For a tall dude with 31" draw, I'll go for 60# or so. Feel free to check in to exhange notes on your progress. I read three or four key chapter in BB1 and mostly just came on here for advice and learned by watching. Guys like Pat B. tom Sawyer, George and many others were my teachers.
Dave