I was entrusted with this blank and kit. From my understanding it is real. He collects rare woods from around the world.If what you have is truly American Chestnut then sir, you have a very rare piece of lumber.
American Chestnut was literally wiped out in the late 1800's and early 1900's by a fungus from Asia. There are very few mature trees standing today although efforts are going on to revive the genus.
American Chestnut history