This collection shows evident signs of gradual degradation of structural integrity, and it is therefore urgent that restorers intervene in order to restore a secure state of conservation.

The restoration intervention included numerous objects realized in bronze and ferro of the Decorative Antique department and part of the Christian Museum. They were formerly within the Vatican Apostolic Library property and acquired by the Vatican Museums under the Rescriptum of John Paul II 1.8.1999.

The state of conservation of the bronze pieces was precarious. There was corrosion and oxidation of the metallic alloy and on some of the small decorated objects. They were conducted with the appropriate metal due to the collaboration of the Laboratory for Diagnostics and Restoration of the Museums.

Among the peculiarities of this group of objects is the restoration of a bronze work from the catacomb area, which still retains the cement mortar bedding. The conservation intervention with the scientific investigation of an iron key was realized in medieval times and found to aggregate fibers of the ancient scroll probably used as a form of protection.

The restoration intervention for most objects has had a fundamental role within the chemical stabilization of the constitutive material of the found objects. They were realized with the removal of the unstable and harmful corrosion that manifests itself on the surfaces of the metallic alloys of the products. The removal of the old protective layers, now altered and no longer suitable, was carried out using aliphatic solvents. The intervention concluded with the consolidation and protection of the surfaces.