Excellent work, Mark! And thank you for the link, Bobby!
Mark, you induced me to look through my bag of loose coins from Asia, and I found a 10 won from 1967 and 1, 5, and 10 won from 1968. They are circulated and not nearly as nice as yours, but I'm happy to have them.

Inordinately fascinated by bits of metal with strange markings and figures