Found this item on the boat. The small part is a lid with rubber o ring and the big part is hollow. Does anyone know what it's used for?its A4 paper behind to give an idea of size.
A4 paper weight with O ring cap that is filled with pepper corns for windy days ? 
The fitting in the middle should provide a clue. Does it look like some kind of pivot?
The fitting in the middle is another piece of wood that screws into the main body.
Looks like it's a T- handle for a tool, something like a primitive type of drill or an awl,, in which the bits are stored in the handle under the cap.
It's actually a skillful placed device left by a PO designed to confound and confuse the new owner.
I think it's a sail stitching awl. The handle for one anyway. The needles are stored inside.
