The "R" is not factory. An "R" and an "L" were stamped by the Millers. This is the early version of the Miller selective trigger. When only the "R" is exposed, the right barrel fires first. When the slide is moved all the way to the rear, the "L" is exposed and the left barrel will fire first. When the "S" and the "R" are exposed, the gun is on safe. This is the middle position. I think Bob Beach may be back to tell us about the blued finish.