Hello

For us lookers - I'm sure you have dug all of this out

It seems to clarify:
Your subject Alfred William Chapman's birth was Registered as Alfred James Chapman, mms Wilkinson. His father John's mother is listed in 1891 as: Mother: Elizabeth 62, widow, b Cheshire
The first Census for your subject Alfred William Chapman (with Wife Lizzie, first daughter Edith) after their 1906 Marriage: Gives his place of Birth as
Holloway, which falls in Islington Reg District.
In 1921 at as 19 June, Alfred W Chapman's age is 35Y, 4 mths - indicating birth Feb 1886
In 1939, Alfred W Chapman's DoB is given as 18 Feb 1886 - so expect registration Mar Qtr 1886 Islington
Alfred James Chapman, baptised 18 Apr 1886,
born 18 Feb 1886John Chapman, Greengrocer & Charlotte Chapman. Abode Adams Place
BIRTHS mms WILKINSON - 5 children
William Alfred Chapman SQ 1883 Islington
Alfred James Chapman MQ 1886 Islington
Francis Wren Chapman, SQ 1888, Islington
Henry George Chapman JQ 1891 Islington
Elizabeth Harriet Chapman JQ 1893 Islington
There are baptisms for all 5 of them, in the years of their births - William Alfred in Hackney, and the other 4 all in Islington with abode Adam's place, father John a Greengrocer (2,3), Costermonger (4) and General Dealer (5)
The 1891 Census: at 2a Adams Place, Islington
Head: John Chapman 32, Greengrocer, b Islington
Wife: Charlotte 30, b Islington
Mother: Elizabeth 62, widow, b Cheshire
Son: William 7, b Islington
Son: Alfred 5, b Islington
Son: Frank 2, b Islington
In the 1901 Census: at 4 Eden Grove , Lower Holloway, Islington
John Chapman 43, Fruiterer / Grocer
Wife: Charlotte 40
Son: William 17
Son: Alfred 15
Son Francis 12
All born Islington
Boarder: Benjamin Clark 28, single General Labourer, b Addesham, Bucks
? Where are Henry George b 1891 and Elizabeth Harriet b 1893 (they were alive in 1911)In 1911, they're in Haddenham, Buckinghamshire
https://www.familysearch.org/ark:/61903/1:1:X7V5-4RG?lang=enJohn 53 & Charlotte 50, with sons Francis Wren 22 & Henry George 19 & daughter Elizabeth Harriet 17.
I wonder the eldest William Alfred died sometime between 1901 and 1911, and Alfred James - restyled as Alfred William in his memory?
Found the 1881 (hoping for more clues on John) and an extra child:
1881: at 40 Alsen Road, St Ann Islington (Upper Hololoway)
Head: John Chapman 23, General Dealer, b Islington
Wife: Charlotte 20, b Islington
Son: James 5mths b Islington
Lodger John Mole 33, unm, General Laborer, b Kelshall, Herts
Baby James being the first child, makes sense as John Chapman & Charlotte Wilkinson married 22 Dec 1878
1880 Baptism on 14 Nov.
Joseph James Chapman, born 19 Oct 1880
Father: John Chapman, Greengrocer & Charlotte Chapman
Abode: 41 Alsen Rd, Seven Sisters Road
GRO: Joseph James Chapman, mms Wilkinson, DQ 1880 Islington
He may be the Joseph Chapman who died age 1, registered Mar Qrt 1882 Islington
So seems we're definitely looking for? John Chapman b abt 1858 Islington to:
Father: John Chapman, Fruiterer (as per the 1878 Marriage of son John)
Mother: Elizabeth, b abt 1829 Cheshire (as per 1891 Census with son John)
Unless Elizabeth was a Stepmother - or was mis-named on the Census and is really Caroline nee Fletcher

- definitely understand your befuddlement!!
Do you happen to know who Charotte Wilkinson was - her parents? The 1878 Marriage gave father as James Wilkinson, Carman ( she was a minor and one of the witness' was a James Wilkinson)
cheers
AMBLY