Tony,
Info only re Grandfather Harry Abbott died 1937 aged 41.
Starting with the birth of Eldest son Henry John Abbott. Born as per 1939 war register dob 31.03.1920
His birth address 24, Sidney Street etc as per image.
In 1921 census free index the only person living at no. 24 was a Harry Abbott, aged 24y 10mths, born Islington, Dock Labourer (ex army)
Birth
ABBOTT, HARRY mmn OSBORN
GRO Reference: 1895 S Quarter in ISLINGTON Volume 01B Page 334
Marriage of Parents (Image available on Anc*)-takes you back another generation.
Marriages Jun 1895
Abbott Henry Islington 1b 484
Osborn Ada Islington 1b 484
1901 census.
Piece 181 Folio 107 Page number 28
Household schedule number 196
Household Members (Name) Age Relationship
Mr Abbott 24 Head
Mrs Abbott 24 Wife
Harry Abbott 5 Son
#John S Abbott 1 Son
# ABBOTT, JOHN SIDNEY mmn OSBORN
GRO Reference: 1899 S Quarter in ISLINGTON Volume 01B Page 287
1911 census Piece 888
Household Members (Name) Age Relationship
Henry Abbott 34 Head
Ada Abbott 34 Wife
Harry Abbott 16 Son
John Abbott 12 Son
Albert Abbott 5 Son
1921 finds Henry & Ada at the same address as Harriet Susan in 1939 war register
SS