Portrait Of Leonardo Da Vinci ? - French School Circa 1840

French school French circa 1840
Portrait of Leonardo da Vinci ?
Oil on canvas
H. 27.5 cm ; L. 22 cm

This small portrait from the XIX^th century seems to be a historical portrait of the Florentine master, reflecting on his sketches or writings, mechanical pencil in hand, on a bound notebook.
This canvas, whose details continue on the returns nailed to the stretcher frame, must have been slightly larger. In the lower left corner left, showing a man seated facing the master. Is our painting a preparation for a larger workor simply a portrait slightly recut by the artist ?