I just got this one from eBay. I know what it is; but figured it would make an interesting quiz. This is actually a fairly rare coin and this should be tough, unless you specialize in this area. I will post the description later today. The coin is pretty rough but is identifiable. Seller's pic below--
Divus Galerius AE2 from Alexandria; but I cannot seem to find an example online with just one letter in the reverse fields. Nice coin!
It was tricky because it is an unlisted Antioch posthumous issue, several are known though. Galerius A.D. 311 DIVO MAXIMIANO MAXIMINVS AVG FIL; Laureate head of Galerius to right. AETERNAE MEMORIAE GALERI MAXIMIANI; Large altar with flames, decorated with eagle standing left on wreath, head turned to right and holding wreath in beak; I in right field. In ex ANT RIC VI Antioch -- here is what a nice example looks like
That is indeed a rarity - and with that particular letter in the right field, possibly unique? I couldn't find one exactly like it on ACSearch, anyway.