Hi Greg,
I see your problem & where it all went pear-shaped

The IGI gives an extracted baptism for John Lulham 22/7/1767 at Kingston Upon Thames s/o Thomas & Jane.
The IGI marriage information for John to Elizabeth Harris is member submitted & says it was in Surrey.
Obviously this Sussex marriage can't be your John (unless he married aged 9

)
I've looked on the Surrey Marriage Index & following are the 3 Lulham Male marriages recorded there;
Thomas Lulham to Jane Stone (botp) by licence 11/4/1757, Kingston.
I looked on my copy of Commissary Court of Surrey Marriage Allegations & the details are not there so maybe they applied for the licence at another court. These are obviously the parents of John (1767)
John Lulham to Frances Harwood (botp) by banns 1/5/1820, Wisley, Surrey.
William Lulham to Sarah Taplin by banns 17/7/1826, Thames Ditton, Surrey.
So far no sign of a Surrey marriage of John & the index covers Kingston All Saints so might be worth checking for other churches in the area of this time.
West Surrey Burials;
Frances Lulham - - 1862 aged 65 West Molesey
I would say this was Frances who married John in 1820Hester Lulham 31/1/1828 4 y 6m West Molesey.
Probably one of their children.John Lulham - - 1841 aged 44 West Molesey
Looks like the husband of FrancesWilliam Lulham 23/6/1732 no age Chertsey.
This burial index doesn't cover Kingston which is technically in East Surrey but I've recently seen the FHS has a new CD out which does!
If I can help some more, just let me know,
jane