These would make great table legs. Such densely cast items have souls, you know. When you look inside the crevices, you see only shadows, but you know-not what secrets will be expounded! Perhaps you will find the fangs of a spider, or a diamond earing from a 1920's dame.
Wait... what are you using instead, and where will they go? I agree with the post above--make them into something else!
sell 'em. you have new heater, right? with tentacle like ducts penetrating the sq. nest?