Peter,
I obtained this piece of Ebony from a guy who claimed it was Makassar, but I disagreed. I bought two lengths, this was by far the larger, and the smaller one is definitely Asian Striped Ebony. They both came from Papua New Guinea, thats a fact and adds credence to the ASE. However, I opened this up this evening and I'm not too sure. One way might be to determine the weight as ASE is only 63lbs/cubic foot, Makassar is 66 - The reason its not used in acoustic instrument making because it doesnt transmit the treble notes well. However I dont know if it could be conclusive enough.
I'm going to find the other piece of ASE and post some pictures tomorrow so we can look at the difference.