Cartier Vintage Tank Watch

Cartier Must De Cartier tank watch. 18k gold over sterling silver. (Gold plated, vermeil). Deployment clasp. Blue sapphire crown. Band is very worn. Watch case has scratches and some silvering. There is also some silvering on the edges of the clasp. Works fine. All original parts, screws, etc. No box or papers. Numbers on back: 673828CC. 2415.