These coins are commonly struck over other silver crowns, often Mexico or Peru 8 reales, sometimes Chile pesos, etc. This is the first I have ever come across that is struck on another Brazilian coin of similar type. There is enough evidence of the host coin to identify which type, but that will take more detective work. For one thing, the host had large rosettes on the crest side, and the crest had bigger cross ends. A work in progress. Check out that crazy multiple rim though.
My first thought was multiple strike, but close examination ruled that out. It's definitely an overstrike. I will try to post close up pics of the evidence in the next few days when I'm off from work.
