Antique gilt-brass Rococo ornament of horizontal form, built around a central oval cabochon framed in gadrooning, with bold C-scrolls, acanthus and shell forms sweeping to either side. Almost certainly a furniture or frame mount. The reverse is a dark patinated leaf-shaped backing with a fixing tab.
The horizontal proportion makes this one easy to use: it sits naturally above a doorway, along the top of a bookcase, or centered over a headboard, where a vertical cartouche would fight the line.