No, I don't know which village John was born in, although both the 1901 and the 1911 say Llanerchymedd. However, I may have made a tiny bit of progress because of naming patterns. It suddenly occurred to me that John seems to have kept up with tradition with the naming of his own children - eldest son after his father, (at least, if I'm right about his father being Richard), next son after wife's father, eldest daughter after wife's mother. So - his mother may well have been Catherine, not Margaret, as his second daughter was named Catherine Mary. She was my grandmother and this is the name John put on the 1911 census, whereas I had always been under the impression that she was Kate Mary - as per her birth certificate. Just a thought, but I'm clutching at straws. Pure conjecture, of course, since I can't find John's birth! Just going by the names of his children, which is why I now think that his father may have been Richard, rather than John.
At least I am certain about the names of John's children. The first four were born in Festiniog, with only my grandmother being born, 1904, in Penygraig, Rhondda (Ystradyfodwg), where they were first shown in the 1901 census. I can't find them individually in the 1891, as there are so many girls named Mary Jones and men named John Owen. Am assuming she was still in Festiniog. I think they married in 1892 or 3. First child was born 1893. However, both relevant wedding certs. I bought are, I think, incorrect - one for 13.9.1890 where John is shown as age 23, a farm labourer living in Llanfor and Mary Jones being 21, living in School Street, Penrhyn; the other was definitely wrong - 22.5.1893, John Owen aged 38 living in Lechylched, and Mary Jones, aged 23, in same village. The first is a possible, but her family always lived in New Street, Festiniog, plus this marriage was 'claimed' by someone when I posted details on another site, some years ago.
Back to the drawing board. Any suggestions/info you have would be very gratefully received. Many thanks for your interest.