Museum quality 19th Century Cameo portrait in original case

Exceptional quality carved helmet shell cameo portrait of a woman in profile, wearing a cap reminiscent of a capped half dollar from the 1820s. Her hair is tied in a bun and a he wears a wreath of oak leaves and acorns below the cap, on her chest between armored breasts appears an eagle with his wings spread.  presented in original leather book case of a style later used for daguerreotypes.