Hawksbill sea turtles were almost hunted to extinction for their shells during the Victorian era !! Lots of hair combs were made of them as well as dresser sets and jewelry !! So it really is possible that it is old and allright to own !! Selling would be a different matter as you are the one that must prove its age. You might be better off just donating it to a museum !! I would certainly give your attorney a call before doing anything with it as the fines can get a bit pricey !!