1904 Panama 10 Centimos Error Coin Question

Hello Collectors,

I found this coin where at first I believed I thought there was a foreign substance on it. Upon closer inspection I realized the substance on the coin was actually the coin metal itself. Same material as the coin but stamped into the front of the coin. When I look closely at the extra material on the surface I can see marking from the other side of the coin that are not on the front side. Looking closely I can see details that are on the back side of the coin which looks to be correctly struck? I has to use a jewelers tool to see and hopefully you can see what I mean in attached pictures. I hope you can see well enough but I'm just using my phone camera. The features I see which only are to be on other side of coin are thin parallel lines and what looks to be the sword and gun crossing. Wondering what happened here and have you seen this before with this coin? I also enhanced a picture to make the hard to see details in the error side a bit more visible. Any thoughts on how it happened and if you have seen this before are appreciated? Thanks