Order of Malta 3 Piccioli [solved]

This coin has the same obverse legend as the Numista catalog reference below, but the coat of arms is different.

https://en.numista.com/catalogue/pieces44436.html

This coin came from an old collection (in New Holland Coin Co. holders from about 1950):

http://www.elfreeman2.com/t19/ma23o.jpg

http://www.elfreeman2.com/t19/ma23r.jpg

http://www.elfreeman2.com/t19/ma23h.jpg

The coin is about 15mm.

Is this just a variety, or a different ruler?

Yes, this is a 3 piccioli of Antony de Paula, 1623-1636. Coins and Medals of the Knights of Malta by Schembri lists eight variations. There is a more recent catalog that may have more. See this site for three examples:
http://www.coinsofmalta.com/jag-collection-13-de-paule/

Thank you for the quick reply.