7 SILVER GILT & COPPER KINGS OF BOHEMIA MEDALLIONS: These medallions were offered by Christies in 1982 and possibly again in 1991. Christie's experts describe the medallions as ''silver-gilt over copper.... constructed of a very thin silver sheet over a copper core.''. In a 1982 memo from Christies to the consignor, ''they appear to be Kings of Bohemia. ...the general opinion seems to be that the most likely place of manufacture is Prague and they are probably late 16th century.'' In a 1992 memo from Christies to the consignor, they indicate that the auction value would be $2000-$3000.