This highly original Minerva was designed as an archaeological excavation object with some parts missing. An example of similar bronze is Tullio Lombardo's Eve, now in Vienna, made without limbs in imitation of excavated bronzes (Montague op. Cit. page 42). Also the so-called "Girl from Boreas", a naked girl with a turban, a fine excavated bronze found with missing limbs, was often replicated until the 19th century.
Literature: Jennifer Montagu, Bronzi, U. Mursia & C., Milan, 1965, page. 42.