Portrait ancestor XIXth in a frame medallion Napoleon III

Superb portrait of a nineteenth century man in an oval napoleon III frame in blackened wood and under glass. The glass is flat (not curved) The paint is most likely a gouache on cardboard. Unable to check because the back has not been opened. What is unusual is that this portrait is a painting, because more generally black and white photos are found in this type of frame. In very good general condition, there is a very small restoration not very visible on the perimeter of the frame (see photo) the mat is slightly off-center. The painting is not signed. Very nice room! Height: 39 cm. Width: 34 cm. Thickness: 2.5 cm.