So I was in my LGS picking up some ammo for my new Kel-tec PMR-30 when I saw what I think is a Arsenal sgl-21. I looked it over and realized its used and an Arsenal not a Fime group with a sticker of $900. Then I noticed some rust on the brake and that's where the negotiations started Because it looks like someone shot some corrosive ammo in it and didn't clean the brake. After some wheel and dealing I ended up picking it up for $750 due to the brake not coming off and a little surface rust in the brake NO where else. Everything else including the bore looks new and hardly used. So what do you guys think what model is it sgl 21 something? My plan is to soak brake and then dump a few mags then try to remove the brake. Anyone have any experience with this?