Updated June 4, 2019:
Hello Stephen,
Thank you for sending further high resolution photos which confirm precisely what you originally said about this particular clock. I have reworded the appraisal for you and updated the value.
TITLE:
Louis XVIth, Gilt bronze, ormolu and variegated white marble, double spring driven, eight-day time and strike, figural mantel clock, theme of a young maiden with two playful putti, made by ‘Dubuc of Paris’, made in Paris, France circa 1790-1800.
DESCRIPTION:
Case – 12.5” X 10.5” X 5” Fire gilt bronze figural mantel clock case with a variegated white marble architectural base with its rounded façade projecting forward and ornamented with ormolu rosette mounts to either side and, in bas relief, there is a panel of mythological figures (? putti) at the center flanked by two gilt rectilinear panels. The base sits on toupie brass feet. A vertical cylindrical plinth of white marble holds the clock movement/dial and sits on the flat surface of the platform while surrounded by the polished golden bronze figures of a Classical female (‘Amor’) in a diaphanous garment playing with a winged cherub above the dial while a second gilt cherub looks quizzically at the dial. A laurel wreath sits above the bezel centrally above the knurled edge glazed bezel. Golden foliage is draped around the upper part of the dial. The back of the case has a circular aperture for access to the movement compartment.

Dial – Circular white porcelain dial with Arabic hours which are scalloped to the inside with colorful wreaths of flowers, open dotted minute ring with Arabic days of the month from 1-31 around the dial perimeter for the calendar function of the dial. A small round aperture is seen above the twelve for a silk thread suspension. The gilt skeletonized hands are very much in the style of Louis XVIth. There is a rather broad steel calendar hand which is likely a replacement (these were usually quite thin and delicate). The lower dial center is signed ‘Dubuc a Paris’. The base of the dial is signed in red for the dial painter, Coteau (Joseph Coteau- 1740-1801).

Movement – A round solid brass plate movement connected with tubular pillars which are pinned at the back plate, anchor escapement, steel cut pinions, steel arbors, and short pendulum rod with attached small brass bob hangs from what originally was a silk thread suspension, now rope. The movement is powered by a two barrel-springs of eight day duration and strikes with a countwheel (seen on the backplate) on the hour and half hour on a silvered bell. The movement is signed ‘Dubuc, Paris’.

Condition/Commentary:
Case – There is chipping along the upper edge of the white marble platform. The case and figures are in overall very fine condition but do have some oxidative speckling. The figures are well executed. The facial characteristics lack the extreme detail of most Dubuc 18th century clocks. These are well done gilt bronze figures. When one looks at the body of work by Jean-Baptiste Dubuc (1743–1819) it becomes clear that he worked with cases that were primarily fire gilded bronze, and his figures have extraordinary features and facial expressions. The clothing, the carts and all the paraphernalia that stood on his clock platforms were golden bronze and expertly executed. Most of the bases used for his clocks were also finely detailed fire gilt bronze rather than marble.

Dial – The dial is in very good condition with no hairline fractures, but few chips along its edges. The use of colorful floral wreaths scalloping the hours from the inside is not usually found during the late 18th century French clocks, but it is certainly in this example. This is generally NOT seen during the 18th century in France and much more common a century later.
The presence of a small aperture above the twelve was seen during the 18th century (before the invention of the aperture used by Achille Brocot in the 1840s with spring suspensions). It was not commonly seen on Coteau dials but I have found other examples signed by Coteau that used such an aperture.
During the 18th century a small hole is sometimes seen in that position to wind a silk thread suspension, thereby altering the speed of a movement (such I the case here). At this point having examined the dial with high resolution photos I have no reason to doubt that this IS a dial made by Joseph Coteau, the most renowned enameler of his time. (Coteau is known to have worked with most of the best contemporary Parisian clockmakers.)

Movement - All Dubuc movements were made with silk thread suspensions, many had rectilinear rather than round brass plates and all were usually signed with large script signatures or simply printed at the base of the movement, as seen here. His movements all had outside count-wheels for striking.

Overall condition is very fine to excellent and although I believe the figures are not Dubuc on his very best day, it remains a very fine example of French clockmaking and would do well on the auction market. I believe that such a clock, signed by the bronzier/clockmaker, Dubuc, and the dial painter, Coteau, would sell in the $10,000-$15,000 range if put at auction today and on a retail basis you could easily double or triple those figures
At last you present me with some clearly visible evidence to back up your original statements about this clock. The close-up photos make it clear that this mantel clock was made at the end of the 18th century in Paris, France, and made by two of the best artisans in their field.
Thank you for following up and providing me with answers to the questions I originally had about this clock. Best of luck with it and I hope you continue to enjoy it.
My best,
David

____________________________________________________________________________________________________________
Hello Stephen,
Thank you for sending in this lovely mantel clock. In the interest of accuracy, I will have to ask you a few questions about your clock, your description of it, and the photos you have supplied which are not of high enough resolution to satisfy my curiosity.
(1) - The Movement - You state, "the works and the face inscribed 'Dubuc a Paris' ". Could you supply me with a close up of the signature or the mark on the rear plate that says Dubuc? Please take off the bell from its post when you take your photos. In addition, can you tell me if there is a silk thread suspension on the back plate or is it a spring type of suspension? A close up view of the pendulum suspension at the upper part of the back plate would really help.
(2) - The Dial: You State, "Enamel face signed: Coteau". Can you send me a photo of the signature of Coteau on your dial? In addition, am I correct in assuming the aperture over the twelve on the dial is a Brocot aperture for changing the speed of the movement?
(3) - Could you show me the pendulum and its bob? They are currently hidden by the bell. Simply unscrew the bell.
(4) - Could you send me a good photo of the face of the female figure?
Once I receive an answer from you I will proceed with my appraisal of your clock. If you are unable to supply the photos requested just attempt to answer the questions I posed and i will try to be of help in doing this appraisal.
Thank you for your cooperation.
My best,
David