Joseph Coteau (Born 1740 – died 1801)
He is established as master of the Parisian Guild of enamellers in 1785. Although it is unusual  for the clock not to be signed by a Clock maker it is not unknown, as Jean-Dominique Augarde illustrates in his book Les Ouvriers Du Temps on page 103 with an unsigned Skeleton clock also with enamel dials by Coteau.

Measurements

DIMENSIONS CM INCHES
Width: 41 16.25
Depth: 13 5.25
Height: 48 19