Well the title pretty much says it all... I bought this gun used, and it was an excellent deal so I decided I would buy it and re-finish it if need be. In the picture it looks like it's just gunk, but it's a lot of gray splotches/stains that won't come off with solvent and a decent amount of elbow grease... It's present in all the slide serrations, but that's the only place I see it. So, any ideas on how to get rid of it? I'm pretty sure I could send it to SA and get it refinished if it comes to that, but I would rather not, since I'm leaving town for a couple weeks and want to have it with me... Thanks ahead of time!