The business strike and proof shown for comparison. This one has almost the same gap in the bottom step, and they both have a mark in the left obverse field. The OP’s coin is a good circulation find!
I thought there was something off about the coin when I was looking at it yesterday. I agree, the coin looks plated. The reverse shows circulation in the middle of the steps. Also the two pillars at the bottom of the steps have ornate raised areas in the middle of the pillar. That is not there. The columns of the monument have no visible vertical lines. The lettering in the motto is not squared off. Plated.