NIGERIA: 50 Kobo (ND 1973-78) in blue and purple on multicolor unpt. Central Bank of Nigeria building at center on face. S/N: "DG/75 129372". WMK: Heraldic eagle. Signature #4. Inside holder by PMG "Superb Gem Unc 67 EPQ". (Pick 14d) & (Spink CBN B13d).