thank you to everyone who responded to/helped spread my post about the mystery skull!
I’ve had an email from one of the lovely scientists at the natural history museum and he says that it’s a partial skull; we only have the cranium. it’s missing the lower mandible (those strange horn-looking pieces are the parts that would connect the jaw to the skull - the skull is actually upside down in my pictures!) and the front section which would consist of the eye sockets/nose/mouth
howEVER he says based on the size, shape and where it was found, it most likely belonged to a juvenile grey seal