Many of the coins have the phrase "Nero Caesar" in the inscription. For the importance of this phrase and the parallel "Neron Caesar" for the Nero Rediturus myth and the Number of the Beast in the Book of Revelation, see here and links.
For an attempt to reconstruct the appearance of Nero and other Roman emperors, see here. I think that reconstruction of Nero looks most like his Type II coins.
I also noted a recent book on Nero here.
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