I just bought this coin because I think it may be unofficial. The bust is quite unusual for Trier- it is too small, there is a lot of room left above the head of Constantine and his chest is much smaller than normally depicted. Other than that, it looks fine, but my first impression was not official. I don't have the weight or measurement yet.
For comparison, the second picture is a more typical example of RIC VII Trier 342.
