In 1940, Smith & Wesson released a .22 caliber revolver on their medium-size "K-frame" that was equipped with a taller rear sight and the new "short action" lockwork. Termed the "Masterpiece", its production was continued after the war.
The postwar "K-22 Masterpiece" contained everything Smith had learned about making an accurate revolver. The barrel featured an less tapered contour and had a serrated rib on top, which provided a glare-reducing sighting plane. The rear sight was of the micrometer style, click-adjustable for windage and elevation. The triggers were serrated and provided with an internal overtravel stop.
Built on a frame intended for .38-class cartridges, the K-22's were mild shooters and extremely accurate, as well as very durable. Starting in 1949, they were cataloged in two distinct styles: With a 6" barrel and a squared-off Patridge-style front sight as the "K-22 Target Masterpiece", and with a 4" barrel and a quick-draw ramp front sight as the "K-22 Combat Masterpiece". With the changeover to model numbers in 1957, these became the "Model 17" and "Model 18", respectively.
Popular with a broad cross-section of shooters, from competitive target shooters, to hikers, to casual plinkers, the 17 and 18 stayed in production for many years. The Model 17 remained in the catalog in one variant or another until 1999, while the 4" Model 18 was discontinued in 1985. The Model 17 was gradually superseded in the lineup by the stainless steel Model 617, but the K-22 Combat Masterpiece had no real official successor until it was recently re-released as a limited production "Classic Model".
The pictured revolver is a K-22 Combat Masterpiece produced in early 1955 (the upper sideplate screw was deleted in that year.) It was acquired at a gun show in Indianapolis in March of 2009. The asking price was in the mid-$500 range, which was pushing the envelope for what is an 85-90% gun at best. It shows wear on the ejector rod and front sight, and the target stocks are incorrect, but that last is easily fixed on Gunbroker or eBay.
The Standard Catalog of Smith & Wesson, 3rd Edition gives a value of $350 for a "Very Good" specimen and $435 for an "Excellent" example, but these values are a couple years old, which is an eternity in the volatile market of 5-screw Smiths. If I found a pre-'57 K-22 in good, shootable mechanical condition that didn't look like it had been dragged behind a truck for less than five bills, I'd probably jump on it.
As they say, you rarely pay too much; you only buy too soon.