Hi Ladyhawk,
Thanks for the extra links. I am not sure about either Mary or John of Ilford Street at this stage. The John Jackson I am interested in is the father of Joseph Jackson born 2 Sept 1807 and baptised 18 Mar 1808, son of John Jackson and Elizabeth Emerson (sometimes Emmerson) at St John on the Haymarket, Liverpool. Their address was Bevington Street. John and Elizabeth were married by licence (she was a minor) in 1801 at Kirk Merrington in Durham. He was born in Barnard Castle c 1775 and she was born in Witton le Wear, Durham Mar 1784.
They had 3 children in Durham, John born 9 Dec 1801, Elizabeth b 10 Nov 1803 d. 6 Apr 1804 and Elizabeth(2) b. 2 Feb 1805, all baptised in Kirk Merrington.
It's period after they arrived in Liverpool c 1806 I am interested in.
Once they arrived in Liverpool, they settled in the lower Vauxhall district and St John was their parish church. Joseph was then born Sep 1807, followed by Charles b. 1812. Daughter Elizabeth(2) may have died in Mar 1813 and was buried at St Nicholas, Liverpool (not confirmed). The next unconfirmed event is the possible death of Elizabeth the mother with her burial at St John on 23 May 1820 aged 37. Husband John's address was Gerard Street and his occupation was dealer in marine stores. Gore's Directory for 1825 and 1825 show a John Jackson shopkeeper at 5 Bedford Street, not far from Gerard Street. His son Joseph by then an engineer had premises at 21 Bedford Street. (I am fairly happy with Joseph from then on).
So long story short, if Elizabeth b. 1784 did die in 1820, then John could have remarried to someone named Mary by the time of the 1841 Census. There are 6 possible parish and civil marriages of a John Jackson to a Mary in Liverpool over the period 1820 to 1840, with none showing the groom as a widower. Indeed, any of these could be John the son born 1801. Sorting out this occupation is just one step in trying to rule this man in or out at this stage.
And thanks to Rhododendron and hepburn for your suggestions.