This is definitely a Franch Mantle clock - not Ansonia. The movement was manufactured by Samuel Marti. He operated in Paris France from 1867-1889. He was awarded the Bronze Medallion in 1860.
Therefore, my guess would be around 1860-1880 for the year of manufacture. Because the movement is marked in would be more valuable. In terms of value I would suggest that you look on EBay Worldwide and watch similar clocks to see what value they sell for. My guess would be around £200-£300 GBP.
Hope this helps