Can't find much Military only James Newport 1st Batt Gordon Highlanders attested 15 Aug 1878 discharged 13 Aug 1884 so do not know if this is your man. Did find the following, 1891 census Church Buildings Charlton Horethorne Wincanton, he is a Groom, Married to Jane [b.1859 North Cadbury] 3 Children Arthur 1886, William 1888, Olive 1891. Jane dies Dec Qtr 1898 age 40 in Wincanton District.
1901 Census Sherborne Road, Henstridge, Wincanton, James is now a Coachman Domestic, now married to Louisa [b.1870 Kilmartin] 2 Children William and Elsie b 1893. 1911 census Back Abbey Sherborne, he is a Stud Groom Domestic, M to Louisa 3 children Doris 1906, Gwendoline 1908, Leslie 1911 all born Sherborne. His second wife Louisa dies Dec Qtr 1919 in Sherborne District.
Possible death a James Newport is buried Union Chapel Sherborne Dorset but the dates are indecipherable.
his son William is a Domestic Stableman at the Rectory Stables, Trent, Sherborne on the 1911 census. His daughter Olive is a Under House Maid to Annie Brury Benthall widow of Kent House Marlborough Road, Bournemouth 1911 census.