RARE Vintage Large 18k YG White Opal Enamel Sapphire and Diamond Owl Pin Brooch

18k yellow gold (stamped), 18k white gold (pin back)
Weight: 48.2g
Solid and Heavy
Hallmarked: 750 160 AL
2 AAA quality genuine oval blue sapphire cabochon eyes aprx. 6.50mm x 5.25mm each surrounded by a halo of 18 single cut round diamonds aprx. 1.7mm each, diamonds are VS-SI in clarity and G-H in color
Very rare and has not been produced since 1970's
Double prong pin back is tight and works perfect
Measures 50mm high x 53mm wide

This is a pre-owned estate piece, in very good condition (slight chipped enamel)
Please see pictures for reference