Your coin appears to be a Kingdom of Sicily ½ tari struck at the Messina mint: https://www.acsearch.info/search.html?id=10747199.
If you can check the weight (about 1.2 grams), this would confim it.
From other coins struck at this mint with the initials PP reverse, it is probably from the 1570s.
We would be grateful if you could edit your title to read: Help with old coin identification (Sicily, Philip II, ½ tari)