Solved: Genuine Tetricus I Coin

It's genuine.

Genuine, just from a different mint, or at least not the usual engraver. Probably from early in his reign before the mint knew what he looked like.

Looks real. His coins in good condition are common since a hoard containing loads of them was broken up, but coins with both the obverse and reverse well struck can be hard to come across.

Postumus tore Gaul (and Hispania and Britain) away from Rome and began putting the empire to shame by restoring creativity and good artistry to coinage, issuing sestertii and even denarii made of actual silver. The gallic empire coinage represents one of the last hurrahs of ancient numismatics (Carausius would do something similar). He was very successful, but was eventually assassinated by Laelianus, who himself was quickly deposed by Marius, who was them himself quickly deposed by Victorinus. Under Victorinus...well, the Gallic empire did okay, but it was no longer the powerhouse it was under Postumus. The earliest of Victorinus' coinage bears the likeness of Marius and, in turn, the earliest coinage of Tetricus bears the likeness of Victorinus. This seems to be for no other reason than the mint not knowing what he looked like, but being immediately put to work issuing his coinage, which is noted for other emperors around the time, for example, the pre-reform coinage of Aurelian bears a bust very similar to that of Claudius Gothicus. This coin has a lot of Victorinus-esque features and is likely an early issue.

Tetricus, to his credit, produced a lot of very interesting coins, with jugate busts and facing portraits and the likes. Eventually, Gaul was restored to Rome, though in unclear circumstances. Historians suggest that Tetricus may have been allowed to retire and live out the rest of his life out in the countryside.

I have a similarly-styled Tetricus antoninianus - I'll have to dig it out and image it.

Except for Tetricus and his son Tetricus II, every Gallic emperor was murdered between 269-273, and not a single one had a successor lined up. Needless to say, confusion abounded, and there was even a lengthy interregnum between the death of Victorinus (killed for seducing his officer's wife) and the elevation of Tetricus - During this time Victorinus' mother ruled, but sadly we don't have any coins.

There were at least two "official" mints in the Gallic empire, probably Trier and Cologne. However, as the political situation destabilized, local mints started opening - many appear to have been made by the local village blacksmith, but others are convincing in style.