I’ve now got hold of Wallraff’s book with its list of fragments of Philip of Side – thank you to the chap who made that possible – now I must actually look at it, and start seeing what other bits exist. Unfortunately the article is in German, but machine translators are a wonderful thing. I might digest down the list of fragments for public consumption.
I’ve also had an email that part of the materials from the Dialogue at the court of the Sassanids which contains fragments of Philip is already in English, albeit misattributed to Julius Africanus, here.
I also learn that portions of the catalogue of fragments by Katharina Heyden are online in preview form here. Also a related monograph is here.