I have a Smith and Wesson Model 57 No Dash Serial Number N346XXX (1975/76) with a 6" barrel, in the original case, with tools and documents from S&W. It's also never been fired. I've been dying to shoot it but I'm also flirting with the idea of selling it, so don't want to ruin the value by doing so. How much are these going for these days? Since S&W released the Classic Series Model 57 has the demand for the older (no dash model) increased or decreased?