The Humanist: 18th Century Oval portrait of an Aristocrat

What is so wonderful and unusual about this 18th Century portrait is the relatability of the sitter. There is an openness to the world in his gaze, curiosity, a sense of humour, passion - how different from the stiltedness found in so many old master portraits done by lesser hands. 
Here, we are clearly dealing with a humanist, a thinker. He does not deep it necessary to wear a wig - an accessory on its way to becoming a stuffy status symbol by the 1770s. What else can we tell about him? The discreet verdigris silk of his jacket indicates that he is from the North of France - gentlemen from the Southern regions favoured more colourful dress. Our sitters is also almost certainly an aristocrat, as the "tabatiere" snuff box in his hand appears so precious that it could only belong to a member of the ruling class. 
Our portrait is unsigned, but has a strong attribution to the Northern French master Celestin Cellier (1745-1793).
Numerous works by the artist are in the Museum of Fine Arts of his home town of Valenciennes near the Belgian border and in the Museum of Fine Arts in Tours. Another work attributed to the artist featured recently at an exhibition in the Musée Lambinet in Versailles. 
Our painting, conserved on its original canvas, measures 64 x 52 cm without its original 18th Century frame.