I think my upper black cover for the front bumper came from Pershing. It's not perfect. A little too short, or the retainer clips are stuck on too low making ride a bit high. In either case, it doesn't come down to the "step" in the stamped bumper. In fact, it slightly exposes a fraction of one of the retainer holes just below the lower edge of the piece.
On the other hand, I replaced the lower gray valance with an aftermarket version I got brand new though a local wrecking yard. It fit very well, though it was missing 2 holes that retainers from my original black upper piece go through. These are near the ends below the turn signal housings. My Pershing upper piece did not have these retainers. If I was flush with cash, I'd get an upper through the wrecking yard.
-Jay