I have a dendrochronology working at my house today trying to date the timbers. Basically they take a core sample of the wood and match the core to known growth patterns to determine when the tree was cut down. Anyways he had a guy in Germany fabricate some core sample bits years ago but the guy is retired now and he is looking have 5 or 6 new one made. The are like a hole saw without a center guide bit and then take 1/2 cores and they have a very deep reach of about 12 to 18 inches. If anybody knows of a place that fabricates specialty tools like this let me know.