Very interesting and informative thread. Always learn something while here. My two were purchased used and I cannot guarantee originality, but they came to me as pictured with no extra barrels, so I can only assume original. One is s/n 152xx, integral sight with lower ramp and no plug (I added the Herrett grips as originals were modified beyond repair. It also came to me drilled and tapped and wearing an old Leupold 2x in a Conetrol mount.) #2 is s/n 197xx, non-integral sight with a different shaped blade, plug below muzzle. Both have the convex muzzle. I have never seen the ramp sight, either plain or red insert, but as noted...I always learn something here.