I guess it was the Combat Selector. It had an allen-type set screw to adjust the sight side to side. I'm pretty sure it is a MkV though, because it has a dull finish all over and wooden grips. I'ts going to be petty tough to find a sight, I have a feeling. What is "Detnics USA"? Are they going to be making Detonics again? And what about "New Detonics"? Are they all the same company as the original Detonics? I am very interested in learning as much as I can about these great guns. Thanks again for the quick replies.