Hello and welcome.

What the OP is referring to is the very commonly encountered crude brass replica of a tetradrachm from Gela. Randygeki's post was one of many containing one that you can find on the forum,
here. The only legible text on these pieces is the word "COPY" and the Greek name of the city's mythical founder, Gelas, which looks like CEAAT or CEAAE to people who aren't expecting the letters to be Greek. Anyone doing a Google search for "CEAAT coin" will likely find one of our threads, like that one.
As I posted in
this thread with one, an
entry in the FORVM fakes database lists these as having been mass-mailed out in an effort by Readers Digest or some similar company to advertise a book on ancient Greece. The huge hole in the bull-man was placed there by the people that made the replicas, in order to hold a blob of glue to attach the coin to a piece of cardboard. I have never seen one of these coins still attached to the cardboard. And once removed from the cardboard, the reason for its existence becomes forgotten. As such, it has to be one of the most confusion-causing replicas out there. Do a forum search for "fake gela tetradrachm" and you'll find a couple dozen threads posted by people in the same situation as the OP.
Age, I would guess sometime from the late 20th century. Value, very minimal, given how many of them are out there - a dollar or so at most. I own one, which was given to me by a member of another coin forum when I bought some (genuine) coins off him.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis