Friday mystery object #482

Happy Friday everyone!

This week I have a mystery object for you that came in as an enquiry from a regular donor to the Dead Zoo’s collections. It was found by a fisherman in the Irish Sea, just off Howth, which is a lovely seaside village on a peninsula that marks the northern tip of Dublin Bay :

Any thoughts on what it might be? I suspect some of you will have a pretty good idea, so keep your suggestions cryptic if you can, so everyone has a chance to figure it out for themselves. I hope you have fun figuring it out!