Find Ancestors

Am hoping someone could help me find my Great Grandfather and his parents/siblings. His name was John Lock and he lived in the Lambeth area of London. He is on the census there for 1891 & 1901. He is listed on them as being born in Ely, Cambridgeshire circa 1849. On 1891 census his wife given as Sarah and on 1901 her name was given as Kate!? My Nan was born to John between these dates and the name of her mother on her birth certificate was given as Sarah Prichard! Though an elderly aunt remembers she was called Kate? Any help would be greatly appreciated.

Could this be him on the 1851 census?

Name: John Lock
Age: 2
Estimated Birth Year: abt 1849
Relation: Son
Father's Name: Henry
Mother's Name: Susan
Gender: Male
Where born: Ely St Mary, Cambridgeshire, England

Civil Parish: Ely St Mary
County/Island: Cambridgeshire
Country: England

Street address:

Occupation:

Condition as to marriage:

Disability: View Image

Registration district: Ely
Sub-registration district: Haddenham
ED, institution, or vessel: 3b
Neighbors: View others on page
Household schedule number: 19
Household Members: Name Age
Daniel Lock 2 Mo
Henry Lock 30
John Lock 2
Maria Lock 3
Susan Lock 23


Yvonne