Spot reblue?

[Lugerdoc]

Mike, It's been my experience that this procedure wll potect the previously unblued surfaces, but will not match the original rust/salt blue. For best results, it's best to remove the original blue from an entire area (barrel, grip strap, etc) and cold blue it to a dark color, allow to dry, and then thin it down with a stainless brush to a color approximating the orig blue. TH