You are on the right track Kirk. Evidently I left 3 rings for you to chase, sorry for the confusion. Plan on using the first fat ring, and have the next for a backup. 1 1/2" at the handle is perfect, fat of that you'll be taking off anyway. But always leave yourself room for surprises if you can. I don't think that stave has many knot or features such that which ring you pick will become an issue anyway. Just get down to it without marking it if you can.
Plan on making your bow 60# @ 28". You can always adjust it after you get it shot in. Again, leaving room for surprises. Also, your bow will draw 60# in this weather, I imagine the humidity in your shop is below 30% right now, and perhaps as low as 55# when it's 90 and 90% humidity this summer. Nature of the beast.
Take your time buddy. If it takes a week to get the first ring off end to end, so be it. Time is the one ingredient you can pour into a project in abundance and do no harm whatsoever. Doing nothing is a problem, but doing stuff slow always works in your favor. We'll still be here if you don't get done until March... seriously, March.
Be thinking about a caul or method to straighten that stave. I think I've posted picture of mine. Looks very similar to a form for laying up glass. You'll use it to clamp to, as you apply heat and correct portions of the stave. I like to put about 2" of reflex into a stave before I start tillering, and then finish nearly straight or perhaps a smidge of reflex. You can do it without a caul. Just be thinking of how to hem it up while you correct and clamp it. Up against a stiff plank with shims will work, bearing in mind we'll be shaping it in two planes (side to side and back to belly).
Have you got a "paint stripper" type heat gun?
We need that if possible. We actually need it pretty much as requisite, and if you are gonna do many more selfbows it's an investment that will pay back many, many times it's cost. I'd make it a top 3 in terms of tools one must have... at least to work with osage, vine maple and the misshapen stuff, even the perfect staves. I thnk they are about $30 at the home center.
You and hegde on this other thread got my mind wandering to my own projects occasionally. Thanks for that. This passion has carried me for nearly a decade now, psychologically. I'm almost embarassed to say it's as much a part of my nature, karma if you wiil, now as my family, hunting or nearly any other aspect of life.