Antique c1750s French Portrait Miniature Snuff Box, 18k, Silver Pique, Tortoise Shell Box

A beautiful woman who would have lived during the reign of French King Louis XIV, XV and perhaps XVI, this hand painted miniature dates c. 1740-50s and is beautifully preserved for such advanced age, atop the lathe-carved tortoise shell snuff box. Lots of individually set pique decoration in 18k gold (acid-tested), nickel silver (lower than .800) and a lower grade gold or perhaps brass. Complicated, the pieces incised one by one and cut, set into the tortoise shell. The painting is shown in our photos only through the convex cover glass, as I didn't want to dismount it. The cover glass is quite clean, and it shows the painting is also clean and undamaged. No signature and no ID, but her fashion and that of the box each assure the date. Box is 3 1/8" in diameter, 1 1/8" tall, closed. It does close smoothly over a silver and 18k gold vermeil lip. There are no gold marks. We have plenty of examples, museum and our own, from this period that have that thin (but not foil) 18k gold front on