Pictures made in Africa however I made the mistake and put over top stove in kitchen
Here's a post I wrote about cleaning copper that might help - https://chascrazycreations.com/copper-cleaning-hacks/
Hi Jack, Mix 1 tbsp of flour, 1 tbsp of salt, and 1 tbsp of vinegar into a paste. Spread the paste on copper or brass, and let it dry, then wipe off with a damp, clean cloth
Hi Jack, Rub onto brass or copper with a soft cloth. Rinse with water and dry. Vinegar and Salt. If copper is tarnished, boil article in a pot of water with 1 tablespoon salt and 1 cup white vinegar for several hours. Hope this video helps I know you can't really boil a piece of art
Wipe with a Mr. Clean Magic Eraser followed by Windex on an old, clean tshirt.