Who would want those bronze heads anyway? They are not very attractive and ownership can get a billion people mad at you. Time to return them to China.
Those bronze heads were crafted by an Italian jesuit as part of a fountain that was itself part of a private amusement park for the Qianlong emperor. Apparently a later empress shared your opinion and thought the things ugly and ordered them removed and put into storage. The looters who ended up taking them likely ransacked them from a warehouse.