Can y’all help me identify this Smith and Wesson? I think it is a pre model 10, factory nickel with a 6 inch barrel. But I can’t find any others like it. It has a serrated trigger, and has an extra feature under the spur on the hammer. The front sight isn’t a half circle either, rather it has a serrated/angled face. This was passed down to me, and I wanted just a little background information.