Thanks all for your replies. Everyone has been pretty helpful.
Going back to "I am a spammer firm" I do believe my Grandpa probably purchased these coins at some tourist
shop in Europe back in the day. He was quite an avid coin collector. He collected mostly American coins but
had somewhat of an interest in
ancient coins. Knowing him, he probably
had a stash of "black box coins" just like the ones he gave me. Oh well, since Im a newbie collector this has given me some insight on how to spot
fakes.