BULGARIA: 20 Leva (1987) in silver (0,500). National arms, date and denomination below on obverse. Bust of Vasil Levsky on reverse. Inside slab by NGC "MINT ERROR PF 66 ULTRA CAMEO / OBVERSE STRUCK THROUGH / VASIL LEVSKY". Cert number: 6389132-089. (KM 164) & (Nikolov 205).