18” Emperor Porcelain Enameled Charger

Open to offers while I research its appropriate value. This antique, Chinese Republic era, heavily decorated, 18” enameled porcelain charger features an emperor wearing robes embroidered with dragons, and seated on a raised dais over a tiger, all on a geometric floral carpet. Blossoms, dragons, phoenix, and other fiery, mythical animals ring him. The 4-character red back stamp is unfamiliar to me. There is a chip and hairline crack descending from the chip. Chinoiserie Famille Noir