Azores Terceira 1829 Cast 80 Reis, Strange Indentations? Ideas?

I have a cast 1829 Terceira 80 reis, that has two strange circular indentations on the date side. I don't know what to make of it, my first thought is that the coin was in a vise to enable finishing the edges, which are filed (as all others seem to be on this cast issue). The back side shows some flattening opposite these "circles" but the circles aren't fully flat on the bottom, like one would expect from a vice. Given that the bottoms of the circles aren't entirely different from the coin surfaces, I am wondering if it was cast this way, but can't figure out the meaning. Have any of you seen ones like this, or ideas? Thanks