Can you post a picture?

My guess without seeing them is that you did get plated tokens. Maybe someone plated them to take advantage of the brass weight and claim they are solid silver then, especially since many strikes are stamped .999 fine silver on the rim. I don't believe there are any known examples of the two you mentioned being minted in solid silver. Even prototypes of $10 strikes are still made with the silver and brass combo.

Dave.