This looks like the right Wm Callow:

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1851
2188/422/27
11 Fairview Place, Toxteth Park, LP, Lancs

Name Age
William Callow 28
Ellenor Callow 27
William Callow 8
John Killip 31

joiner foreman
JK lodger unm joiner
all b Ramsey

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Liverpool marriages and banns:

Liverpool, Lancashire, England, Marriages and Banns, 1813-1921
about William Callow
Name: William Callow
Age: Full Age
Marriage Date: 30 Jul 1846
Parish: Walton On The Hill St Thomas
Spouse's Name: Eleanor Corkhill
Father's Name: Char Callow
Spouse Father's Name: John Corkhill

Image shows:
William Callow/full age/bachelor/joiner/Fletcher St/father Chas Callow, farmer.
Eleanor Corkhill/full age/spinster/Lodge Lane, Windsor ?/father John Corkhill, farmer.
William signed/Eleanor x-mark
witnesses: James Gelling+Jane Hussey.

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So son William b 1843 was born prior to the 1846 marriage. I can't find a likely birth in IGI.

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William senior's baptism:
name: William Callow
gender: Male
baptism/christening date: 27 Apr 1823
baptism/christening place: MAUGHOLD,ISLE OF MAN,ENGLAND
birth date:
birthplace:
death date:
name note:
race:
father's name: Charles Callow
father's birthplace:
father's age:
mother's name: Is. Kermod
mother's birthplace:
mother's age:
indexing project (batch) number: C03817-1
system origin: England-ODM
source film number: 106183, 106735
reference number:

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1841
Dreemskerry, Maughold

Ancestry's transcription (Callear should be Callow)
Name Age
Charles Callear 55
Isabella Callear 56
Charles Callear 15
William Callear 15
John Le Callear 15

WC 15 joiner's ap

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Jean C