Thank you very much for all the suggestions you sent through. I really appreciate them. Re Jerry's birth - yes, there are two possibilities, both for 1775 which I am sure is his birth year. It ties in with the census record and also his death certificate in 1758 which I obtained. He is named Jeremiah in his birth to John and Betty, (lived in Carcote Saddleworth) and named Jerry in his birth to Sarah Buckley, a spinster (Lynthwaites Saddleworth). I had ruled out Jerry's marriage to Mary Shaw in 1809 as a second marriage because it usually says on the marriage entry "widow" if the first wife had died, but I guess it's possible that was just an omission by whoever wrote the entry in the church register. So yes, it is possible that he married a woman called Mary prior to 1800 when John was born. That would mean that his first wife, Mary, died some time between 1802, when their daughter Mary was born and 1809, when he married for the second time (to Mary Shaw). I've been hopefully searching Ancestry this morning but I can't find a definite death for her. There are deaths for Mary Buckley in that period in the right general area but since she was married I'd expect the record to say Mary Buckley, wife of Jerry Buckley. I can't find any that say that. So yet another question mark. Re Jerry's children, the only baptism record I have found is for John in 1800. I can't find any others pre or post 1809. The only reason I found they had a daughter Mary is because the Joseph Mason you mention in the 1841 census is Jerry's grandson. His daughter Mary married a man called Joseph Mason. Mary died young and I was able to get a rough birth year from the death entry, which would be 1802/3. As I can't find a baptism for her it's possible Jerry had other children too, who either weren't baptised or were baptised in a church whose records haven't been put on Ancestry. You mention how unusual the name Jerry is. You're right - there are very few Jerry Buckleys but it is a strong family name in my line, which for generations followed the traditional naming pattern of naming the first son after the paternal grandfather. So I have Jerry Buckley (born 1881) who was the son of Benjamin Buckley (born 1859) who was the son of Jerrey Buckley (unusual spelling, born 1816) who was the son of Benjamin Buckley, born 1793/4 (birth year assessed from census and death records). Naturally I was expecting Benjamin born 1793 to be the son of a Jerry Buckley, assuming the naming pattern continued. In terms of age it's possible Jerry could be Benjamin's father. He would have been 18 or 19 when he married for the first time which is feasible. But with no record of a first marriage and no definite record of a death for his first wife I'm left with as many questions as answers. Frustrating, isn't it!
A few more things that puzzle me... The Benjamin born in 1793 married Ann Mallalieu and they eventually ended up at a pub called the Temple Inn in Waterhead. Intriguingly, in the 1871 census Joseph Mason (Jerry's grandson) is living with his family right next door to Benjamin Buckley's widow, Ann. It's possibly just coincidence as Joseph was a collier and was at a different address in each census. On the other hand... could there be something in it? Finally, I have Jerry's death certificate for 1858. He was no longer living at Cotemanheights (his abode in the 1841 census) but was widowed and had moved to a place called Back o th' meadows, which is less than a mile from the Temple Inn (where Benjamin lived prior to his death). The notifier for Jerry's death is a man called Buckley Bower, (born around 1823, so much younger that Jerry) who lived in Birks. Birks is very close to the Temple Inn and Back o'th meadows. I've yet to discover how he fits into the Buckley picture. If Jerry was indeed Benjamin's father, I would expect Benjamin to have notified Jerry's death, not Buckley Bower. I would really value any suggestions for getting further with this. I seem to go round in ever decreasing circles.