Congratulations. And I agree that the Vatican Philip is one of the great Roman portraits
. Pat L.
P.S. Being interested in Philip, if you don't have it already, you probably would like to read Michael Peachin, "Philip's Progress: from Mesopotamia
to Rome in A. D. 244, in Historia: Zeitschrift für Alte Geschichte
vol. 40, no. 3 (1991), pp. 331-342.
If your library doesn't have that multi-lingual periodical, you can get it through JSTOR. He does refer to coins, but not so much as I hoped; it is Philip that he is interested in. He wishes to correct the cartoon-character encapsulation that we usually get. I chanced upon this when I was tracking down Ann Johnston's article on Caracalla's travels. It is good, when you give a reference to a periodical with a Latin title, like Historia, to provide the rest, so that one can find it in LOC, for example, as being in German, so far as the title and publication are concerned, and confined to ancient history.