I recently received an antoninianus of Gallienus with a VICTORIA AVG reverse and with SPQR in the exergue, very similar to this one (although not as nice): https://www.acsearch.info/search.html?id=165792 RIC attributes all these SPQR mint marks to an unidentified Asian mint. Any dated coins (P M TR P XVI or XVII) with this mint mark are dated 268 A.D. When I scroll through ACSearch for coins with these mint marks, I find some dealers attribute them to Antioch, some (like this dealer) to Cyzicus, one to Smyrna, and many to "Asian" mint. Any idea for why this discrepancy? Has some new scholarship assigned coins with this mint mark to a specific mint and/or time?