Hi and welcome to the Forum!
Your K-22 Masterpiece Model 17-2 was made in 1966. These are very fine target revolvers and are highly regarded by all of us. I myself have owned several of them over the years and all have been fine shooting revolvers.
The "dash numbers" used in S&W model designations represent progressive engineering changes in each model line. In the case of the Model 17, the dash 2 indicates a re-engineered cylinder stop mechanism which resulted in the elimination of the screw that was formerly located in the front of the trigger guard. In collector parlance, this was the beginning of the "three screw frame." This change was made in 1961.
Enjoy your new acquisition!