Ken - get some BLACK LOCUST, a second to osage orange in hardness. I
saw some today on Ebay. Not a common lumber but it will turn well with
sharp tools. The chap on Ebay had cants 2-3/4 x 3" about 42 inches long
at a reasonable price. Blocks coule be bolted together to attain larger
sizes. Search for "black locust lumber". Double check the specs on
hardness, but I think you will find the Black locust much harder than
hickory or rock maple. The only question I would have is durability
with repeated pressings. Fine details may wear away. Jim