I picked up a 686-6, Plus 1 with a seemingly distinctive serial number. It's CZB30XX. I'm wondering what or if there's any significance to the CZB prefix. The revolver has the 2.75" full lug barrel, Hogue-ish S&W grips, adjustable rear and red ramp front sights, and is pretty bright/polished. The hammer is bobbed, ad both the hammer and trigger look chromed. It has a very nice trigger job, with light, smooth DA and almost too light SA. Thanks for any help or thoughts.