Could this be the Lost Cob of MM?

[cbrg148]

48 years ago my mother, a friend and I went to Key West. My mom' friend bought my mom a Piece of Eight.
She kept it years and then it went *poof*. About 2 years ago I found this in some of her stuff. Is this the Lost Cobb of MM (My Mother)?

Can someone tell me if this is real? I have not weighed it yet. But, if it comes up at 27g, what say you all?

And is there somewhere that can authenticate it and provide me a COA?

 

[ToddsPoint]

Take it to a coin shop and they can send it to NCG or PCGS for authentication and grading. They will put it in a slab. A good coin shop should be able to authenticate it without sending it in.