License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Obelle. Rocaille Cartouche with the Abduction of Helen of Troy, from "'Livre D'Ornemens Inventes & Dessines Par J. O. Meissonnier (...)", 1734. The Metropolitan Museum of Art.