Arlo is definitely on the up. Ruby appears to already be enjoying a spike in popularity. I agree that, with the current vogue in Edwardian names (ds's middle name is Arthur), we might be due a 30's/40's revival.
I predict a minor and short-lived spike for Effie, as it it is quite sweet, trips off the tongue lightly and there's one in 'Desperate Romantics'. (Not that I'm watching, but someone must be!)
I love all the votes for Violet. I wanted that for dd, but dh exercised his right of veto. I also liked Ernest for ds, and Betsy had he been a girl, so clearly there's some kind of turn of the 20th century thing going on in my head.
I can't get my head around the possibility of Nigel or Neville making a comeback, which must mean that they are ripe for revival. I will probably get grandsons named that, now I've said it.
I can't imagine an Atticus or Ptolemy living round here. (I am now picturing grandsons called Ptolemy Nigel and Neville Atticus.)