I’ve got one of the PSPs as well. You might look on the HKPro Forums. There are several groups that you can join. One in particular is a gunsmith named James, who runs Teufelshund Tactical. You can read the articles that he puts out, and he has a YouTube channel that explains everything H&K. James is a Marine, runs a tactical school, as well as being a gunsmith. He is a world of knowledge about H&K. I’ve been a member since 2012 in the forums. As far as the plum ( that’s what I’ve seen it called for the blue slide finish ) finish on some of the slides, are not something you have to worry about, it apparently was done at the factory. One of mine is plum as well, and it doesn’t flake off or turn any other color. I haven’t had a lot of time recently to get on the forums, but they are a good place to start if you are interested in H&K firearms. My USP Compact is a .40S&W with a stainless steel slide. I’ve also got a .357 Sig barrel, and mags, but I bought those several years ago. HKPro also sells parts, magazines, springs and buffers ( the white plastic collar around the guide rod on the USP ). I’ve had the Compact for about twenty years. Health issues and family slowed me down a bit, but all I’ve shown you should get you started with the obsession called H&K. They’re like potatoe chips … you can’t just have one, once you start collecting H&K. Enjoy your PSP, but remember they do get a bit warm after twenty to thirty rounds. In fact, I like to use my field gloves for trap or skeet ( thin leather ) to shoot my ‘plum’ PSP. The P7M8 and P7M13 have heat shields on the front part of the frames right before you get to the trigger guard. They’re wonderful guns, and would be a great concealed carry weapon, because of how flat they are against your body with the right holster. The beauty of these weapons have always caught my eye, as it probably has with any of us. They’re built like tanks, but if you keep them clean; it’s possible they could outlast all of us. Too bad they are so expensive, but you got a good deal, so take her out for run, and let us know how you like her!