The rings on HHB are very thin. I wouldn't bother with it, especially if it had so much material to be removed. You could go through all that work only to find that the wood in the core isn't any better.
I would saw it up into boards, and see what you can do with them. If you can get a decent board out of it, build a board bow and back it with linen or sinew or even another slab of wood like hickory.
I think you are setting your self up for frustration and disappointment after a good deal of work by trying to chase a ring on what you described. But hey, you're the one who can actually see and feel the wood, so follow your instincts, if you think you can get a self-bow out of it give it a try. The worst that can happen is that you end up where you started but a bit wiser and more experienced.