I recently purchased a Colt Python with 6" bbl in Royal Blue from a private party. It was manufactured in 1980. The gun is in excellent shape save for the fact that it had been stored in a gun rug zipped up for a good 15 years. Surprisingly, it showed almost no surface corrosion, which many such stored firearms do without benefit of desiccant to absorb the inherent moisture from inside the rug. There were only two very small areas about the size of the head of a pin where surface corrosion appeared. Following a complete and thorough bore cleaning as well as complete disassembly, cleaning, and lubrication, I attacked the two areas of corrosion with a Q-Tip soaked with Kroil. It required a lot of elbow grease but the results were dramatic. The corrosion was almost completely removed without removing any of the bluing. Just looking at the arm, one would be hard pressed to locate where there had been any evidence of corrosion at all. Fortunately, no pitting had occurred. That would have been a different story. I tried a similar effort one time on another gun using Flitz. It got rid of the corrosion... and the bluing in that spot. Just my two cents.