Both pens at the edges near the bushings have been fragile I guess you would say - I have enough of "meat" there but it seems to break off in tiny pieces leaving a rough edge and I can not get the finish that everyone talks about it having - Could be my method but I do not have trouble like this one the other woods:icon_scra
The grain
is running down the pen?
Anyway, African Blackwood feels more like other woods under the tool, but if it's ebony you want, then it might simply take a bit of time to get a feel for it. To me it feels friable and "chippy" as well, especially immediately after working with other woods. I have used Macassar and Gabon, BTW. There are other ebonies, of course, including our very own Persimmon.
I have to use exceedingly sharp tools on ebony: a skew with the heel ground off (grind off that heel! if you are catching a bit with the back of the skew you are...um...skewed), a roughing out gouge, a narrow parting tool, and one of a handful of variously sized three-cornered tools we make for ourselves from round files. For finishing a "hard" edge, such as what you are describing where the bushing fits, I use the parting tool or a 3-cornered one, although I would not hesitate to run a piece a bit long and then bring the edge to a sanding plate if it were being difficult. We make & restore chess sets, so the flat edges for us are the bottoms of collars and the very bases--not entirely dissimilar to pens: small and exacting!
For finishing, we use sandpaper, then 0000 steel wool, and then chami leather impregnated & dried with colourless auto refinishing fluid: 3M from AutoZone. :icon_cheers
~M.