Would appear to be a S&W Number 1 Second Issue. But, that S/N doesn't appear to be correct. I believe the S/N's only went up to 126361. They were built between 1860 and 1868. This is a black powder .22 Short, but would not be safe to fire with current mfg. .22 shorts, they would be too powerful. Double check on the butt of the gun for the S/N. Is it possibly "1189XX"? I would rate the condition about Fair to Good, which would place it's value in the $200 to $300 range, from what I can see.
These are very early and interesting pistols.