Antique Tucking Hair Comb with Provenance 1800s Vulcanite, with Old repair

ERA: True vintage item from the 1840s
MEASUREMENTS: 3 inches wide by 2-7/8 inches
MATERIAL: I believe that is is vulcanite
Molded, one piece hair comb. It is a brown/black material. I believe that it is vulcanite. It comes with a note of provenance 'Grandmother Hawkins tucking comb, about 1830'. On researching vulcanite, it came into use in the 1840s, so the date on the note may be incorrect, or it may be a material other than vulcanite. The middle tooth on the comb is shorter and pointy-er. It looks like maybe it broke and was filed down. It's an old repair.
CONDITION: Very good condition. It was probably a darker black, it is now a dull black with slight brown shade.