The 'C' couronné poinçon was a tax mark used on any alloy containing copper between March 1745 and February 1749.
These bronze allegories of the seasons (Saturn, Ceres, Bacchus, Flora) were used by Boulle frequently on various types of furniture. Notably, they appear on a set of four cabinets by André-Charles Boulle in Versailles, illustrated in P. Arizzoli-Clémentel, Versailles: Furniture of the Royal Palace, 17th and 18th Centuries, vol. 2, Dijon, 2002, pp. 36-37.