I wonder if we may be connected. If not, as you have a brother who still lives in the village, I would be grateful for information about the village, and any history.
My gg grandfather, John Jones, was born in Llanymawddwy in 1805. He had several siblings (unfortunately, none called Owen). His grandfather (Richard Griffiths) spent (I think) all his married life in Llanymawddwy in a farm called Troed y Rhiw. The trouble with patronymics is that the surname is never a good guide to actual relations.