Hello, The Assay Master is Ludwig Christian Zuk, in office in Riga 1856-1884 and the maker is JAL, Johann Andreas Leischke, apprenticed 1825-1829 to Johann Arved Eckström, still mentioned active 1873. V. Vilite, no. 229, p. 76, Latvijas Sudrabkali , Riga 1993; and A. Leistikow, p. 324, Baltisches Si...