"{T}here are estimated to be more than 5,000 varieties of sang pyong tong bo coins with many varieties still undocumented. The authoritative Korean coin catalog {(Hanja: }高丽朝鲜时代货币{)} documents 3,078 varieties of the One Mun, Two Mun and Five Mun coins, and 48 varieties of the One Hundred Mun coin.” (Source: Primaltrek/Primal Trek by Gary Ashkenazy)
Note 📝: Some mint marks were used by different government mints, for that reason this list doesn't contain 52 (fifty-two) entries, while it does represent all the 52 mints operated by the Korean government.
Korean Money / 韓國銀行 發券部 (1982), from the Bank of Korea's Digital Library. A book 📖 that can help you identify Korean cash coins and modern coinage. This book 📖 was written by the government of South-Korea, and can be viewed gratis here.
Korean Currency / 韓國銀行 發券部 (編), the 1994 sequel to the aforementioned book 📖 by the government of South-Korea, this book is also hosted on the website of the Bank of Korea’s online library and can be found here.