If you study heavily-circulated examples of this South Korean coin, you will begin to notice the overall wear patterns on the main device (Admiral Yi Sun-shin's face). Traces of wear begin to become evident in About Uncirculated examples (far left) which exhibit, what looks like, just a little "cabinet friction" on Admiral Yi's nose, left cheek, and extending over the left eyeball to the forehead and center of the hat band. If one of these coins stays in circulation,this general wear pattern begins to flatten out these features until they become well-worn in these areas of the face. One possible "die variety" on which collectors in Korea have commented is the depth of the hat band. This incuse design element seems to be sharper and deeply-struck in some coins with even more overall wear than other coins in higher grades. I'm not sure if the date of the coins matter in all of this. Is this what explains the Krause Catalog's claims of "die varieties" for 1974 and 1975? This is something that I need to look more into with more circulated examples of this coin...
