Thanks for all the positive comments.
What is "ebonizing"? I soaked some steel wool in vinegar for a couple of days, shaking it a little now and then, and then strained the liquid into another container. The resulting liquid is basically used like a stain and applied after sanding and before finishing with CA/BLO.
The liquid does not look particularly black, but if I had applied several coats the timber would have finished up very dark. As it was, I gave it only one light coat.
This process works better on some timbers than others, and I would suggest trying it on scraps before a nice pen on the lathe that is all but finished.
For comparison sake, this Sedona was made from the same board.