Hey Guys, So I've gained a lot of interest in Gen 2 Glocks after acquiring my first one back in March '18. Since then, I've added 4 more to the collection. My most recent acquisition was a 17 from GunBroker, advertised as being in nearly new condition. After I finally got the gun home, I took it down for a cleaning. As soon as I started fiddling with it, I noticed the slide appeared to be a bit "off" in color. I held my phone light up to the slide, and sure enough it appears orange. My guess would be this is surface rust. To my understanding, Glocks (especially pre-2011) used a Tenifer process to treat the metal and help protect against rust, corrosion, etc. After inspecting this gun, it's evident it has not been handled or shot much at all, however the slide is definitely orange. I used some RemOil and a cotton cloth to try and wipe it off, no luck. My cotton rags would turn orange/brown after excessive wiping, but the "orange film" is still evident. I can only notice it when I hold a light up to it, or I'm holding the pistol at an angle. I'm looking for any help as to what exactly is happening to my slide, and how I can fix this if possible. I've read and searched about soaking for hours even days in vinegar, Hoppes, Coke, WD-40, CorrosionX, etc., along with using a 0000 steel wool pad. I figured I would reach out to the community for some do's and don'ts before attempting anything myself. In the pictures, I have the 17 next to another 17 Gen2 I have, both 5 digit serial numbers beginning with M. The last two pictures more or less show how the gun was photographed and marketed to me. As you can see in the last two photos, nothing seems to be out of the ordinary or cause me to question the finish; not to mention it's a Glock, and slide rust isn't usually something I'm looking out for when purchasing one. Any help or information regarding this matter would be greatly appreciated. Thanks guys.