It looks to me to be early 1900's.Say 1910-1930 ish. The S and F reference is a regulator meaning slow and fast. The other marking are not of any particular reference. If the clock is not working it could be that it needs a clean or the balance wheel is not working. Either way any good clock shop should be able to repair the clock without problem. In terms of value - if it only a time piece - no repeating mechanism or chiming mechanism - then my best guess would be between $150-$250. However, you could track similar clocks on EBay worldwide to see what they sell for. Hope this helps.