https://www.metmuseum.org/art/collection/search/198376
Johann Lorenz Natter - William Ponsonby, Viscount Duncannon, Future Second Earl of Bessborough -...
Signature: Engraved on ground below neck: L. NATTER F.Inscription: Engraved on ground at left edge: W. LORD DUNCANNONMarking: Unmarked
johann lorenz natterwilliam ponsonbyviscount duncannon