Got it back today but the receipt just said "fitted barrel to frame and function tested". My secret markings tell me that none of the little parts were swapped out. So I really don't know what they did but, it works. I got it too late today to test fire, that will have to wait until Friday. What's another two days. Oh yeah, the Decelerator grip fits the frame well and gives me a tad more room to reach the trigger, feels great too.