My parents found this shuttle a few years ago in an antique shop in England.
I have considered the possibility that it might have been intended as a knotting shuttle, as those were generally much larger than tatting shuttles. On the other hand, knotting shuttles were large so that they could hold a lot of thread, so this doesn't really fit the bill. Plus, knotting shuttles were usually very ornate, since that craft functioned as much to show off the knotter's elegant hands as to actually make anything.
I'm thinking that it may be a sort of "transitional" shuttle, made during the time period when knotting was declining and tatting was ascending. In this case, it would be understandable that a shuttle maker might not know what a knotter/ tatter really wanted from her shuttle, and he might have been trying to make something that would be useable for both crafts, if not ideal for either. I'd be interested to hear other people's ideas.
I believe it is ivory.
It came wound with this horrid yellow and green perle cotton.
Jane would say, grotty colors, these threads are stiff, rough, thick, and full of knots. I certainly hope that some poor soul wasn't trying to learn to tat with this shuttle and these threads-- that would be enough to put you off tatting forever!
I'm giving the thread to Squijum. At least he can get some pleasure out of it.