Hi Brian,
A search of the 1911 census index shows only one Sidney Coulson born Sunderland, but he is Sidney Frederick, aged 3, wonder if any of your papers show his middle name - his birth reg is Dec Qu 1907 Sunderland
There's a family in 1901, father Thomas, mother Hannah, and according to the 1911 index they have Sidney in their household, so it's possibly his family:
1901 census: RG13 Piece 4722 Folio 89
79 Brandling St, Roker, Sunderland, Durham
COULSON
Thomas head m 36 Bricklayer's Labourer Sunderland
Hannah wife m 32 Northumberland Newcastle on Tyne
Charles son 11 Durham Washington
Thomas " 4 months " Sunderland
Barbara
