I just got this really nice example of an unofficial issue. If you did not look carefully, this coin would have easily passed as official.
Constantine I
Circa A.D. 318- 319
17x18mm 2.9gm
CONSTA-NTINVS AVG; laureate helmet and cuirassed bust right.
VICTORIAE LAETAE PRINC PERP; two Victories stg., facing one another, together holding shield inscribed VOT PR on altar inscribed with a diamond shape.
In ex. PLN
cf. RIC VII London 161