Whilst looking for the family in 1901 or 1911, I found a Thomas Vary, b Dublin, who was a costermonger (ie hawker). His "wife" was Alice, and their children had mmn Vickery.
There's no marriage for Vary/Vickery in the suggested timescale, but there are actually 2 marriages between a Thomas Vary and an Alice Vickery years later - in 1916 and then again (!) in 1929, both in Camberwell which is where this family lived in earlier censuses.
And that got me thinking. What if Thomas and Ellen's marital state was, shall we say, flexible? (only 2 children in 20 years is unusual, after all!) And what if surname usage was equally flexible?
That doesn't get us a lot further, but just to say that neither can I find any appropriate birth in the suggested county of Devon for the 10 yr old Frank R that I can see, "in care" in 1911 (is that cryptic enough not to count as a look up?)
This is probably completely irrelevant but in the absence of anything else obvious I was trying to think laterally.
I'm still a bit worried about whether Patrick born in Aug 1901 and Frank born in Feb 1902 are actually the same person.