Antique French S Marti Oak & Slate Mantle Clock

This antique French mantle clock is maker marked i believe S. Marti on the works along with some other wording which is difficult to read. It is made of oak and possibly slate as it is every heavy weighing in at about 20 pounds. The left side top has some upper movement of which we believe it is pinned construction and because the clock is so heavy that likely is why but we are not sure.  It seems to run temporarily then stop so for these reasons it is being sold as is.There is also a screw from the back into the base and the clock measures about 13 1/2" wide x 13" tall.