Here is a coin that must be unofficial- A Helena obverse paired with a SARMATIA DEVICTA reverse. The style seems decent, but the chance of this mule being produced officially seems very small, even though the SARMATIA issue did directly precede issues with Helena.
Circa A.D. 324
16x17mm 2.7gm
FL HELENA AVGVSTA; diademed & draped bust right, hair in elaborate coiffure.
SARMATIA DEVICTA ; Victory advancing r., holding trophy, palm branch, spurning captive std. on ground to right
