3.5 years after my first post... I have found my John Williams' birth in Llanbadrig 1849, found his parents' marriage also Llanbadrig - they were William Williams and Mary Hughes. Can't find WW's birth yet - 1841 census says "of this parish" ie Llanbadrig, 1851 says he was born in Landrygarn, 1861 has what looks like Bordwyn, marriage lines say he was from Aberffraw.......
to make matters even more amusing - John Williams born 1849 was son of William Williams and
Mary Hughes. JW married in 1871 - guess what his wife's name was?
Mary Hughes daughter of John Hughes and Elizabeth
Williams - give me another few years and I might work this lot out