Kirk,
The grain doesn't follow the stave all that well. Study the rough layout I penciled on it, you don't have much more than 1/8" leeway off of that layout, without risking violations.
In fact it gets downright wiggly in places and you'll see that layout runs right to the edge in places.
You need to take two rings off the back, to get down to that nice fat one if I remember right, and I made it a point to think it through and remember right.
You can make 50# at 29" no problem, but you can't afford to take off that knotty part on the straighter end. Rather, again following my layout, you run past it to one side.
Study my layout and figure out why I put it down like I did.
This project won't allow for an arbitrary design and layout, like a pyramid shape or whatever. Save that for a nice clean whitewood stave or a board or boo backed project. Rather follow the grain along it's wiggly path and plan for about 1 1/2 width from fades to midlimb like was already suggested. Then, again following the grain, you'll taper out to about 1/2" at the string grooves. but initially leave it about 1/4" generous of that until you get it floor tillered and then get the one limb pushed over enough to make the string track.
Once you get the size down to floor tiller, it's a simple easy matter to move that limb over with heat. It will be intimidating perhaps for the first timer, but we'll give you detailed instruction... I can post pics as I'm sure can others.
I layout a 4" handle and 2" fade tapers and then work them down from there near the end of the project, once I get a short string on it. I generally leave no more than 7" of none working wood.
These bows are 60# @ 28", 58" ntn, typical for me not bending handles and if any not much more than 1 1/2" at the fades... and neither from the caliber of wood you got dispite is knarly shape. You got wood aplenty brother, but you are definately in the right mindset. Take nothing for granted.