I purchased a P2000 a few months ago and recently I just noticed some odd marks on the finish near the ejection port (see picture with the marks noted in the red area.) It almost looks like copper fouling got on the slide, but it didn't come off with some Hoppes #9. It's not pitted, and the gun has been stored in a dry area so I can't imagine its rust but I just don't know. Any ideas? I'm not a handgun appearance perfectionist, but if its rust I want to make sure to stop it before it spreads.