An Incomparable Pair of 18th Century Venetian Palazzo Parcel-Gilt, Polychrome, Mother-of-Pearl and Semi-Precious Stone Accented Mirrors, each retaining their original bisected mercury plates, and each surmounted by scrolling carved giltwood acanthus crests inset with etched mother-of-pearl, the corners embellished with Siena marble cabochons inlaid with conforming etched mother-of-pearl and surrounded by giltwood egg and dart moulding along with additional exuberant giltwood acanthus leaves, against a ground decorated with colorful polychrome exotic figures, floral and foliate motifs