I installed a set of XS Big Dot sights on a pistol of mine. I failed to notice that the rear sight, V notch with single white line, wasn't centered exactly before I applied a copious amount of red Loctite all the way around that rear sight and even in the set screw holes. After I wiped off the excess Loctite I put the pistol away and didn't look at it again until the next day, at which time I noticed that it wasn't centered. It wasn't off by much, but any amount discernible with the naked eye was too much for me. So I tried to take it off. I couldn't get it off. Believe me I tried. I had to take the gun to a gunsmith, and he had to use a torch with a good hot blue flame to apply enough heat to deactivate or melt the Loctite. Now to my dilemma. Apparently the heat from the torch scorched the sight, because the bluing is noticeably duller than it was before, as was the white line also. The sight wasn't exactly blued black in the first place, but it was a good bit darker than it is now. According to XS Sight Systems the sight is made from chromoly steel. I have already cleaned, degreased, and repainted the white line with a more lustrous white fingernail polish, now I need to touch up the sight body itself. What product do you all recommend for that task? A gun bluing pen or gun black pen or what exactly. I want to do it right, but you must understand that I can't take the sight off to do it. When I tried to remove the sight myself I stripped the set screw heads, so when the gunsmith reinstalled the sight, properly centered, he Loctited it down, and advised me that it would never come off again. Thank you.