Seems to happen a few times per a decade, but a genuine Kings Island Smurf is currently for sale on eBay. At the time of this post, it's up to $260.55 with 5 days left. If I had to guess though, I'd expect this guy to fetch $600-$700 by auction's end.
https://www.ebay.com/itm/153230145471?_trksid=p2471758.m4703
Smurf's Enchanted Voyage opened in 1984 (not 1982, as several online sources falsely claim) and closed after the 1991 season. It was a re-skin of the original Enchanted Voyage, which opened with the park in 1972, and was ultimately replaced by Phantom Theater.
Here's some highlights of the ride: