
Here’s some useful bibliography, from a new-ish commentary on the Philippics:
I’m sharing it particularly because it supports my strong suspicion that this is indeed also Tremulus on this later type (RRC 425/1; cf. RRC 293/1 illustrated above):

Update 2/15/2016:
Myles McDonnell makes the point very clearly in a footnote (p. 157):

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