Here is the Table Medal "Proclamation Of The St. Aleksandr Nevski Cathedral Monument 12th September 1924" which was issued during the celebrations of the promotion of the Cathedral to the status of national monument.
The cathedral was built in honour of the Russian liberators of the nation.
It's copper with a chrome like plate. It has had a rough life but this is exactly the sort of thing that was "forbidden" during the People's Republic and the price was right. There is also a portable Medal commemorating this which I will post.