I have a 1900 AE Luger in for restoration. It has a bead sight, perhaps a Marble type but it does not appear to be the gold bead like I am used to, the bead appears silver like it MIGHT be a type of solder. The rub comes in that the front blade is supposed to be fire blued but I am worried that the bead will go away if the metal reaches the temperature to fire blue the sight. Is this an original sight? If so, I wonder how they were made orginally. The sight is the common type of notch sight that is found on most 4 & 3/4" Luger barrels and the silver is in the notch. Could this be a not factory sight that someone simply added the solder to? Thanks!