I believe that this coin is official, but it has had a bit of a double strike, so it is a little blurry around the edges. However, there is always a possibility it is not official, but it would be one of the best unofficial coins I have ever seen.
It’s a hybrid/mule, a Constantine I obverse paired with a CAESARVM NOSTORVM reverse. This reverse type was issued A.D. 323- 324 for Crispus (Trier 440..see 3rd picture) and Constantine II (Trier 441). During this period, the most common obverse for Constantine I was the SARMATIA DEVICTA (see the second picture).
Constantine I
A.D. 323- 324
18mm 2.5gm
CONSTAN TINVS AVG; laureate head right.
CAESARVM NOSTORVM surrounding wreath enclosing VOT X.
In ex. STR crescent
Hybrid
RIC VII Trier 435 obv. with Trier 440 or 441 rev.
