Korean Brown Ceramic Tea Set

Korean brown ceramic teaset, consisting of 7 pieces - teapot, 5 plain cups, tray. The set is in perfect condition, having been in its box for the last 25 years. Each piece has a mark on it. The marks on the teapot and cups are shown in the photos. The teapot has some writing and marks all around its upper parts as shown in the photos. The box lid also has some writing on it, which my Korean friends were unable to decipher - see photo.