This may perhaps be a coin of Alexandria under Nero (cf. RPC 5262). The coin published as DS Supp 3 (Nerone. Corona, dichalkon, anno 10? = D283v.) might indeed be another specimen of the rare D283 = RPC 1, 5262 (value mark I in wreath, rather than year 10), but the obverse does not look much like Nero, and it may perhaps rather be another example of the (probably Neronian) coins with head of Zeus/I in wreath.