In 1955, Smith & Wesson produced a variation of their aluminum-framed Chief's Special Airweight revolver that had a built-in hammer shroud. Called the Bodyguard Airweight, the new revolver allowed the shooter a smooth, snag-free draw from inside a pocket or under clothing, while still allowing the hammer to be thumb-cocked for single action fire, an option not available on the earlier Safety Hammerless and Centennial revolvers with their entirely enclosed hammers.
The model was an instant sales success, with shooters enjoying the availability of both modes of operation in the slick little fourteen-ounce pocket gun. When Smith made the changeover to model numbers in 1957, the Bodyguard Airweight became the "Model 38" and continued selling well. The distinctive silhouette of the Bodyguard had its moment of infamy in the hand of South Vietnamese Gen. Nguyen Ngoc Loan, frozen in Eddie Adams Pulitzer Prize-winning photo.
The Model 38 Bodyguard Airweight was joined by a stainless variant, the Model 638, in 1989. A decade later the stainless gun's sales had so outstripped its carbon steel forebear that the original was dropped from the catalog after a 47-year run. Model 38s remain fairly popular with collectors, but are generally less expensive than Model 37 Chiefs Special Airweight or the Model 42/042 Centennials.
The above revolver, a nickel Model 38 in about 98% condition with box, docs, and tools, was acquired for about $300 back in 2003 which was probably at the outer limit of its value envelope at the time. Currently it might bring as much as $350 with the original stocks fitted and a quick rub with Flitz. But like they say, "You can never pay too much for a gun; you can only buy it too soon."