Jewellery, Watches and Objects of Vertu to include the personal archive of Louis Osman, goldsmith and architect

A ‘tubogas’ necklace, by Cartier, the yellow gold graduated flattened gaspipe-link collar necklace with three raised reeded motifs, signed, stamped ‘750’ and numbered ‘750123’, in a red Cartier pouch, necklace length 41.5cm. £3000-5000