If it were mine...saying this from someone that has done this for many years, I'd split off the bottom 2" then on the top half I'd split it in half. This would give you 2 good staves and a possible 3rd if the bottom one split true. I would take each stave and work down to the first good, clean ring like I said above. Until you get each stave split and start reducing the back you don't know what you have. You won't know how bad the checks are until you get into each stave. Even with a check in the end and a few inches of the back you may still be able to place the bow outline on the stave to miss the checks. Also, checks aren't necessarily bad in a bow if handled properly.
How is the back of the whole stave?
This is a bow I built for a friend that recovered a stave from an island in the Missouri River that he had cut 15 years earlier You can see how badly it was checked...