Rare lacquer and eggshell cigarette case. Gerard Sandoz ? Paul Brandt ?

A rare sterling silver french cigarette case.
Lacquer and eggshell.
French silver hallmark and maker mark (unreadable).
Probably Paul Brand or Gerard Sandoz.
Even possibly Jean Dunand as eggshell work on black part is typical of his work.
Anyway a fantastic piece with highest quality of lacquer and eggshell work.
Circa 1930.
Excellent condition.
13cm 8cm