[lugerholsterrepair]

Dennis, The pin you are missing beneathe the takedown lever is actually the spring that holds the lever in place, keeping it from rotating down when fireing. If it rotates down the sideplate will likely fall off. Try contacting Luger Doc AKA Tom Heller. He will likely have one for you.
You could keep it as its polished..and shoot the pistol..a somewhat worn bore is not going to affect it much..or you could have it blued if you don't like the look of the polished steel. A cheap salt blue is good enough for a shooter. I wouldn't put too much into it..it will always remain a shooter.
Spend your money on a good sound 90% blued pistol. If you plan to shoot it don't worry about all matching..and the price that goes along with that.

Jerry Burney