This pair of busts are after the Sèvres figures probably modeled by Jean-Jacques Bachelier (1724-1805). Bachelier, who began working at Sèvres in 1748, was the Art Director from 1751-93, being in charge of painting as well as being in charge of modelling from 1753-57 and again from 1766-74, after Falconet's departure to Russia.
Between 1769 and 1780, Sèvres produced a series of small statuettes formed as term figures of classical figures, as well as series such as the Four Seasons. All of these have identical bases as the present pair. The only differences being the additions of the tassled cloak at the top and the oak leaves at the base (see E. Bourgeois and G. Lechevalier-Chevignard, Le Biscuit de Sèvres: recueil des modèles de la manufacture de Sèvres au XVIIIe siècle, plates 17 and 18. A similar model, also with a porphyry base was sold from the Rene Fribourg Collection, Sotheby's London, 28 June 1963, lot 156 and is presently in a New York private collection.