Keep the third group unassigned while checking any original capture notes. You can retain its evidence of an imaging problem without inventing which physical cover it represents. Have quality judge the two linked pieces against the appearance requirement independently of those captions.
Keep those accepted reflective surfaces in the comparison rather than choosing duller examples that make the camera's life easier. On our own faceplate work, retaining accepted pieces alongside a rejected one made the different questions much clearer; you still need the appropriate defect examples for yours.
What does that accepted-cover comparison actually show? I'd keep false rejection separate from the missing detection study, so an improvement in one cannot quietly stand in for the other.
That is useful within its scope. Keep the previous strong-band views too, because the next reviewer needs to see what changed and why the new arrangement was considered, not only the prettier results.