"Jacques Charlier (c.1720-1790)? Rare Large Painting On Ivory"
I'm not an expert on this period, so I'll do my best to describe the piece. The work was created on two ivory plaques. One plaque has a crack (see photo). What I've found about this work suggests it might be by Jacques Charlier, who copied works by François Boucher. It's very large for an ivory support. The artwork itself measures 23.3 cm x 16.5 cm. With the frame, it measures 29 cm x 22.8 cm.