I will tell you the approximate age and point of origin of most items, whether old cast bronzes or newly Mass produced ones. Of course the Antiques are the one which keep their values especially the One of a Kind and Unique. Recently the retail market has been flooded with numerous Cheap Mass produced Copies from: Poland, Italy, Belgium, Germany, China, and India. Yes India. (Walmart? Not yet)
Most of these cheap reproduction bronzes do not contain a high percentage of Copper. All Low grade Reproduction “Bronze Castings” contain more: Zinc, Nickel, Bismuth, and Lead, (Yes, Lead). Not even Tin. Since these types of castings are not malleable they tend to Snap, shed chromium, and therefore are much harder to restore.
Quality of the Gold Plating is very important. The Antique items are either Mercury Gold Plated, Gold Plated, Lacquered, however, the Cheap Reproductions are Flash Plated over Chrome Plate. Yes Chromium, to give it the fake and glamorous Shine. After a short while these Cheap Reproductions start to leak a greenish color salt which contains acids.