on early Aurelian coins, the bust sometimes looks a bit like Claudius II and sometimes it looks a lot like him. The first coin below is Aurelian from Rome and the second is Claudius II from Rome. Both were issued in A.D. 270. Apparently the engravers were not sure what Aurelian looked like yet.
The last coin is an Aurelian from Rome struck A.D. 274. Still some similarities, but Aurelian's neck has gotten a bit longer.
