Antique Sessions Mantel Clock 8 Day For Sale

This is for an antique Sessions Black Mantel Clock. An 8 day clock with badly stained top and some bottom front, see pics. I think key and pendulum are original. The clock has been oiled and ran great for a week. When I rewound it I could not get it to run consistently. Don't know what the problem is?? Pivots are tight. Selling as is for parts or repair but I suspect it may be a minor repair??