James Vickress bapt 1809 St Anns Soho, parents were Edward and Maria Charlotte.
Edward is buried Finsbury St Luke 27/08/1835 aged 60
Maria Charlotte buried 18/11/1857 aged 80 Nunhead cemetery
It would appear that Edward and Maria had another son, Thomas bapt 1811 St Ann's Soho
There is another bapt William at St Botolph Aldgate 11/10/1807 having been born 18/08/1807, address given Somerset St.
This doesn't bring you much nearer your man. I do realise that baptisms usually happen within a few weeks of a birth way back when but sometimes they aren't as I have found in the past, 1809, well I don't know?, also I have been told, don't know how true it is that wedding couple's had to be baptised to get married, once again I don't know for sure.
I think you will only find your man through a baptism as registration didn't start till about July 1837
Have you got any witnesses on his marriage in 1815?
Louisa Maud