I have always wondered if I could successfully pass off some late Roman bronze AE3 culls as pennies. Imagine getting a Constantine-era GLORIA EXERCITVS in your change.
A member at my local cigar club found a Follis of Maximian at a Coinstar machine. He brought it to me as he heard I am interested in ancient history and ancient artifacts, and I identified it for him. That's the only such incident I have ever come across of any coinage older than 150+ years old being found or placed in circulation by either myself or someone I know.
Meow does not remember as it was many years ago. Meow just bought a heater core, the loose change was a bonus.
I guess it's a steady state thing. We need to make enough every year to make up for the older ones from ~30+ years ago which are wearing down or no longer circulating. Now that people use electronic transactions more, the amount of wear per year on coins is probably less as the velocity of money in the form of change has probably dropped a bit. But the population growing partially counteracts it.
Or when someone decides to completely cover a car with dimes (Ripley's Believe It Or Not Museum in Key West)