That is a K-22 Masterpiece also referred to as a "pre-model 17."
The serial # dates it to about 1951.
That is a 5-screw gun. The fifth screw is hiding under the horn of the grip on the right side of the revolver.
The picture of the revolver is not clear enough and I would want to know more about it (i.e. original grips, original box, condition?) in order to give a more accurate idea of value. Either the photo is not very representative or the finish is bad on the revolver?
