These latest images now show a laminar structure, which looks too thin for wood grain but may be horn or even tortoiseshell. It also looks to be about 4" long - perfect for a handle. One of your earlier images of the narrow end also showed that this had been reamed out to accommodate whatever 'tool' was inserted. To me it has the jiz of a button hook handle that would make it Victorian/Edwardian. You would need to have a look with a microscope to say more - by all means send it in and I will take a look. email us at firstname.lastname@example.org to make arrangements.