here's another example that recently sold, it looks almost crude compared to the first example. The style seems a little awkward and the campgate is short and blocky. I would call it unofficial, but the legends are perfect; maybe an engraver in training did the bust and reverse design.
Constantius II
A.D. 326
19mm 2.5gm
FL IVL CONSTANTIVS NOB C; Laureate, draped and cuirassed bust left.
PROVIDEN-TIAE CAESS; camp gate with two turrets and star between them.
In ex. P crescent T
RIC VII Ticinum 201