A two-headed coin from the mid-1700s, probably wasn't technically a "
Magician's coin", as stage magicians weren't much of a thing back then though you did sometimes see magic tricks performed at town fairs. It was probably a coin made by a confidence trickster so they could always win a "heads or tails" flip.
As for its age, it probably does actually date from some time around or shortly after the reign of George II, because using a hundred-year-old coin in a confidence trick would defeat the purpose of it pretending to be an ordinary, everyday coin.
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