Watch List notes:

Nero, 54-68. Dupondius (Bronze, 29 mm, 16.24 g, 6 h), Rome, 63. CLAVD CAESAR AVG GERM P M TR P IMP P P Radiate head of Nero to left. Rev. VICTORIA AVGVSTI / S C / II Victory advancing left, holding wreath in her right hand and a palm branch in her left. BMC 219. D. Calomino, Defacing the Past - Damnation and Descecration in Imperial Rome, London, 2017, p. 71, fig. 36 (this coin). RIC 199. WCN 196. An extraordinary coin: with the praenomen Nero removed from the coin and the bust tooled to resemble that of Vespasian as a form of Damnatio Memoriae. Very rare and of immense historical interest. Some deposits, otherwise, very fine.

From an American collection, ex Classical Numismatic Group e336, 8 October 2014, 254.
This remarkable coin illustrates a momentous period in the early history of Imperial Rome, that of the Civil Wars caused by the widespread rebellions against Nero, who had become intensely hated by a wide spectrum of the Roman population. One way people had to express their opinion about a ruler was to modify his coins, either by counter marking with a stamp covering or partially covering the portrait, or by defacing it with cuts or bangs. This ancient practise has been described in modern times as being a form of damnatio memoriae and was long thought to often be done officially. In fact, most of these acts, other than countermarking, were probably done by private people.
This must be a private action, but one done by a truly determined individual, who wanted to not only deface the coin, but to do so in a way that would allow the coin to continue to circulate (deliberately and obviously mutilated coins might not be welcome in trade). What he did was first to excise the emperor's praenomen, Nero. But then he did something amazing, rather akin to the way the coins of Napoleon III were recut into comic portraits after his defeat at Sedan, or US Buffalo nickels had the head of Native American 'Chief' on the obverse carved into a wide variety of heads, primarily of hobos. He carefully worked over the face to completely change its features; in fact, while it might well be that of Vitellius, the whole feel is much more Flavian in nature, and our 'artist-engraver' must have intended this coin to pass as one of Vespasian.
But where was this done? Most likely in the west, perhaps in Italy or Gaul, where Nero was truly hated; in the east, on the contrary, Nero's philhellenic leanings rendered him much more popular - thus precluding the likelihood that the coin was altered there. For a complete, informative and very well illustrated survey of "damatio" on coins, do read the excellent work on the subject by Dario Calomino of the British Museum, cited above.