Morgan Dollar Looks Like A Uniface. No Date, "O" Mint Mark

Hello there, my name is João, I write from Brazil and this is my first post here in the forum. Thank you all for this space and for your time.

This week I bought an interesting Morgan dollar, struck on the reverse and completely flat on the obverse.
I did some research and found about uniface coins but still have not found a picture of a Morgan dollar with this characteristics, only smaller coins. So I'm not sure if there are even original coins like this one.

It has a "O" mint mark and looks very similar to my other "O" Morgan, if it wasn't for the more copper/brass/olive color instead of the usual clean silver. But it does have the silver bling sound. Sounds like silver but looks like copper.

The coin has the regular diameter, is only 16.5 grams, it's thinner than a regular one and the edges are like two steps, as if a reeded coin was struck into a coin with smooth edge.

Have you see one of these? Any idea if it´s a real mint error?







Thank you all and have a nice week :)

João