Thanks so much Jim, this is all really helpful and explains a lot. The previous posts are rather confusing, as they were 'works in progress' at the time.
If it helps, this is the situation as it stands...
Walter Robert Leigh, born 21 Jan 1845 in Southwark, Surrey. Mother died in June 1845, father in March 1851. Walter living with (unmarried) step-mother in North Cray, Kent, and as a boarder, working in a paper mill in St Mary Cray, Kent in 1861.
Crucially he cannot be (or hasn't yet been) found in 1871, and, apart from his marriage and eldest child's birth certs, there is no record of a Walter Leigh/Lee or Packman being in the army, other than the army discharge (Walter Packman), attached.
Walter's sister Elizabeth Caroline Leigh married Henry Packman in 1864; the Packman family emigrated to Australia between 1872 and 1875.
Walter's marriage, death and burial are in red, the children's births between 1877 and 1880 in black, and the 1881 and 1891 census details - where the family is recorded as Packman - in blue. Baptisms of all the children were in Brecon, parents Walter and Mary Ann Leigh.
31 Oct 1876: Walter married Mary Ann Thomas. Walter: age 26 (should be 31), private 24th of foot, Barracks Road, Brecon (certificate)
22 Mar 1877: Walter Roberts Leigh born at Mount Street, Brecknock to Walter Robert Leigh, private 24th foot, and Mary Ann Leigh, formerly Thomas. Informant: W R Leigh, father, Barracks, Brecknock (certificate).
28 Dec 1878: John Richard Packman born at Rhosfach, Blaenporth, Llandygwydd to Walter Robert Packman, coachman, and Mary Ann Packman, formerly Thomas. Informant: M A Packman, mother (certificate)
31 Dec 1880: Thomas Henry Leigh born at Mount Street, Brecknock to Walter Robert Leigh, groom (domestic) and Mary Ann Leigh, formerly Thomas. Informant: M A Leigh, mother (certificate)
3 April 1881 (census): 8 Mount Street, Brecknock, Walter R Packman, age 32, born Alton, Kent, coachman (dom), married to Mary A Packman. Children: Walter R Packman (4), John R Packman (2), Thomas H Packman (4 months)
5 Apr 1891 (census): 27 Struet, Brecon. Walter Packman, age 40, born Foots Cray, Kent, groom, married to Mary A Packman. Children: Walter Packman (14), John Packman (12), Harry Packman (10), plus Elizabeth Packman, Charles Packman (6) and Albert Packman (2)
14 Jun 1891: Walter Robert Leigh died at 2 Aberfan Road, Merthyr Tydfil. Ostler in a coalmine. Cause: pneumonia 7 days; Informant: Sarah Ann Williams, occupier, present at death, 2 Aberfan Road (certificate).
17 Jun 1891: Walter Robert Leigh buried in Brecon (burial ground of St John and St Marys)
Again, many thanks for all your help and advice on this Jim, much appreciated.
The photos are brilliant too loord, many thanks.
Deirdre