A rare gold and enamel notebook charm pendant, late 18th/early19th century, designed as a miniature

A rare gold and enamel notebook charm pendant, late 18th/early19th century, designed as a miniature etui, with openwork floral panels in multicoloured gold against grounds of blue and violet basse-taille enamel, the hinged lid set with plaques inscribed 'SOUVENIR D'AMITIE' ('a memory of friendship') opening to reveal a miniature paper notebook and pencil, length 2.8cm, later early 20th century Dutch assay mark