Never had one that opens quite like this! From the drum shape the locket compartment rolls out from the beautifully engraved outer casing held closed on both sides by a decorated disc.  Remnants of gilding still extant.

JEWEL NOTES

Circa 1870

15ct yellow gold

Without the bail 21mm in diameter

Bail is 7mm long

Double sided interior photo frame is 18mm in diameter

Weight 7.1gm

CODE V554