From a bulk lot (where coins like this abound). The obverse inscription unfortunately reads IMP ........ ANVS P F AVG. The reverse is a typical CONCORDIA MILITVM, Emperor standing r., receiving Victory from Jupiter standing l. Mint and officina mark: K Δ. I put this out in the hopes that somebody who is more familiar with this issue can help me pin it down as to which tetrarch appears on the coin. I realize this might prove impossible.
Ah, yes! Thanks so much! I see from the RIC listing that had it been any other than the Δ officina, it would be impossible to tell!