The National Historic Museum safeguards a valuable collection of metallic heritage artifacts. Considering its relevance, the museum implemented a scientific research project. In that opportunity, X-ray fluorescence and several microanalysis techniques were employed for the qualitative recognition of chemical compositions. After considering the poor condition of certain items as a consequence of former conservation treatments, a critical assessment was developed. As a consequence, the objects that showed more evident deterioration problems were selected for the removal of the products employed in the questionable treatments. Nonabrasive chemical methods were used to restore the original aspect of the objects.