There are some Cleopatra I coins with the head of Isis on the obverse. http://www.ptolemaic.net/NMpdfs/Cleopatra-1-Isis.pdf Egyptian iconography seems to grow more prolific in the Roman era. For example, Canopic jars on the reverses of the large drachmae and mummified forms.
The horn of Ammon is an Egyptian symbol referring to the Egyptian god Amun from pre-Greek times adopted for depictions of Alexander the Great by Ptolemy. Though the association of the ram with Amun was probably regional to the Siwa Oasis and a relatively late addition to Egyptian culture (maybe 8th - 7th century BC). https://www.cngcoins.com/Coin.aspx?CoinID=324571
Don't skip the islands of Kossura and Malta: http://www.wildwinds.com/coins/greece/sicily/cossura/t.html http://www.wildwinds.com/coins/greece/sicily/melita/i.html