Would SKS with access to 1891 /1901 census info be able to find a listing for Sydney (Hill) Thorne B1865 in Newnham in the later census of 1891 or 1901.
He was resident in Gloucester City (Saint John Baptist)Age 15 in 1881. He would be about 26 in 1891. He was the son of Samuel Thorne and Mary Hill of Newnham.
Despite my searches, I have not found him and suspect he may have emigrated.

1871
Samuel Thorn abt 1820 Frampton on Severn, Gloucestershire, England Head Newnham Gloucestershire
Mary Thorn abt 1826 Cambridgeshire, Gloucestershire, England Wife Newnham Gloucestershire
Sidney Thorn abt 1866 Newnham, Gloucestershire, England Son Newnham Gloucestershire
James Thorn abt 1863 Newnham, Gloucestershire, England Son Newnham Gloucestershire

1881 62 Oxford Rd, Gloucester St John Baptist, Gloucestershire, England
Sydney Thorn abt 1866 Newnham, Gloucestershire, England Lodger (Head)

He is working on the Railway ( and lives near the Midland Station ) so I guess he could be anywhere by 1891 !