Before I cleaned them up they were kind of gasoline tarnished. I tried silver polish that didn't really do anything. Then Bar Keeper's Friend and that kind of helped. Then I boiled them with Baking Soda and tried Bar Keeper's Friend again and that did the trick.
They're stamped "Japan" on the bottom. Any silver-plate I've ever had polished up with silver polish...so what are these guys? They shine like silver and are heavy enough.