Demonstrating the point: Vespasian's name starts at the upper right OVEΣΠΑΣΙΑΝΟΣ on this tetradrachm from Antioch. Less clear is my Valerian tet from Alexandria: AK Π ΛΙ (Publius Licinius) OVAΛEPIANOC EVCEB
Great and very interesting explanation, @dougsmit! The most curious and interesting is that it really makes all sense to apply the letter O as a Greek pronunciation of V, although the rest of the alphabet is Latin. Being an unofficial coinage, do you believe it could have been struck in some eastern mint?
I would say it is very likely it was made in an Eastern area. For one thing, at that period of history, most of the action was East not West.