keep you eyes open Jim as it varies in colour and it's possible to get light and dark in one blank. I have some beautiful pieces I've had for many years. I don't know if old bolwling balls are available in the US but worth looking for if they are.
Just found these but they seem over priced, Old Lignum Vitae? Ironwood Bocce,Lawn Bowling Ball 2 lbs 4 oz. 5 5/8" grooved
I've just bought 2 for £10 GDP