Michael, I saw your post earlier today (re the William Dickers death look-up in NYC) and got interested in the mystery of his origins.
Noting that his year of birth was confirmed by the death announcement as circa 1827, and that the most likely candidate in passenger lists was the 21 year old William Dickers who arrived in New York from Ireland in 1848, I wondered if there was a trail to be found in Ireland for this Englishman.
I discovered that Dickers was an extremely unusual name in Ireland but that there was an Edwin Dickers who joined the Royal Ulster Constabulary in 1846. So I had a look for him and found that some contemporary references (court records etc) had his name as
Dicker.
Then I found that Edwin Dicker in the 1901 Dublin census in Mountjoy Street and it seems he was born in London circa 1822
http://www.census.nationalarchives.ie/reels/nai003689509/I found Edwin Dicker's baptism in Westminster, London in 1822. Father
Joseph Dicker of Vincent Street, a "musician 3 Guards" - a soldier. Mother Margaret Dicker.
A couple with the same names, Joseph Dicker a musician and Margaret Dicker, had a son baptised on 7 March 1827 in Lambeth:
William Baylis Dicker. Residence: New Street.
A possibility ?
Postscript: there is a marriage in Southwark (Christ Church) on 19 August 1824 - Joseph Dicker and Margaret Bayliss