Personally I'd give it some more time... the years will slip by on their own... trust me
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If you must cut it, split or saw it into 2 initially then decide if you can reduce it to quarters.
It depends what size bows you hope to get, generally I find it's fewer than you expect.
You may have loads of sapwood and not much heartwood so you won't really know until you cut it.
It's always better to aim for a few good staves than a load of useless ones
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With only 8" at the top you may only get 2 decent warbow staves if there's not much heart wood.
Look upon it as an investment, if you cut it down and find it's not much good you've blown it
Del
PS. IMO there are some optimists here! It will be 4 max if you are lucky.