Master 19cm Japanese Lever Blue Brass vintage automatic knife

Master 19cm Japanese Lever Blue Brass vintage automatic knife made in Japan post 1960 measures 19.2cm (7.5 inches) open and 4 1/8 inches closed with steel liners and brass bolsters & lever. The clip blade is 98% full or better with heavy patina and some spotting and has Master engraved into the face of the blade in cursive and underlined. The scales are blue under clear acrylic and I can see some symbols in gray, but not sure what they are. Scales are in good condition. The knife works well with blade tip well below liners closed, good snap and locks open with about 1/8" movement at the tip. Barely rattles if shaken with blade open (except lever). Good condition.