I'm not sure that this is N. pleurosema because the head shape seems to be different (not blunt looking) and the base of the antennae are not visible as they are in all the images of this species that I can see on the ALA and LBH.
Yes: I am not convinced of the ID as Nola pleurosema. Turner describes Nola pleurosema as having a dark mark along the forewing costa, and this specimen just has three dark costal spots. But to me the forewing tips of this specimen look a little too pointed for it to be a species in Epipaschiinae, in which there are another bunch of grey moths with streaky forewing patterns. Also Nola pleurosema has a wingspan of about 2 cms, which is a bit smaller than this specimen.
If the timing of the observation in May may be regarded as definitive for C. banksiaria I would be happy to go with that, although I would be hard pressed, given the variation visible, to distinguish between a C. banksiaria female from a C. nodosus female on appearance alone. However I note that this specimen seems to lack the strong bold black line nearer the trailing edge of the forewing which is visible on at least two of the images of C. banksiaria females which can be seen on Bold Systems 4. Identified images of C. nodosus on BS4 seem to lack this bold line. I also note that the authors of MoV (Part 5) define the "'C. banksiaria group'' as including the species C. nodosus.
I wasn't trying to say May distinguishes banksiaria and nodosus, they both fly then and not now. I had been thinking the report was of a spring moth. The females of these two sp are indeed similar. I'll compare them at ANIC.
C. nodosus are generally more heavily patterned than C. banksiaria, particularly the males and less so the females. Some C. banksiaria females are quite plain grey, with some darker scaling along the veins. I think this specimen is one of the C. banksiaria group.