A gold and enamel locket pendant, France, circa 1819-1838, designed as a book, its front and back

A gold and enamel locket pendant, France, circa 1819-1838, designed as a book, its front and back covers applied with red, white, blue and green enamel, opening to reveal a hinged series of rectangular locket compartments containing photographs, pendant length 4cm including suspension hoop, early 19th century Parisian assay mark for 18ct gold, maker's mark GRM with ear symbol, hinged photo frames possibly a later addition