If it’s an upper case “L” along with a reduced situation “c”, it’s for Louis C Marks who made jewelry while in the 40s. SETA is an organization that gives fashion jewelry. Their jewellery generally has a CZ plating about silver. CN signifies that the jewellery is produced in China, https://josueizqhx.blogdon.net/top-latest-five-jp88-urban-news-52999420