It's a nice cancel. T.M.V. Doughty was a photographer during the Civil War era. As you noted, the stamp is R14c, which has a catalogue value of $65. The cancel will enhance the value, but from the scan it looks like your stamp is torn, which will diminish the value. I don't know how scarce this particular cancel is, but there are some experts who post on this forum who can probably give you a fairly precise idea of value.
Not only is the stamp torn, but the perfs are trimmed at the bottom. Only part perfs have natural straight edges, and those will have one wide margin. This cancel is not especially scarce, but it is not totally common either. In fine condition it probably would have been about a $100 retail item, but in this condition all the value is in the cancel and 10% of cat is probably about it.