I found wide 6/4 walnut boards that were air dried 10+ years ago. They were stored in a barn in PA in that time and moisture content is still 12-14%. A few questions:

1) How long will they take to dry to where they can be used if I store them in my garage or basement?
2) With boards that old, will there still be concern with checking or warping as they dry to usable range?
3) Any additional concerns with using walnut boards that are air dried, or 10+ yrs old?