Tris, keep quiet about the treasures in our museums, or London will come and take them. They've already raided the Bradford Museum of Film and Photography for a terrific cache of old photos. If they get wind of what we've got up here, it'll go and we'll never get it back. Think about what happened to the Greeks and their marbles.
The only thing keeping us safe at the moment is their fear that there be dragons north of Watford, but, like Tolkien's dwarves, the thought of treasure will draw them.