Considering the close proximity of Pompeii to the city of Rome, and that both this Fresco and the painting described in the story of Roman Charity by Valerius Maximus, were created during the 1st century before the year 79 AD, it is probable this fresco is either the original painting described, or a copy of the original.
The fact this fresco still exists adds credibility to the story of Cimon and Pero as being not only true, but an example that Roman justice was tempered with piety and compassion, rather than being metalled by strict interpretation of law alone.
Note: The original Fresco at Pompeii would have been more vibrant and colorful. The hot volcanic ash from Mount Vesuvius severely damaged this fresco during the eruption; however, the same ash that destroyed Pompeii, also protected what remained.
Had Pompeii not been buried under millions of tons of volcanic ash, what remained would likely have been razed and rebuilt, and we would have never known of this fresco's existence.