Yep, seen the marriage certificate that mentioned he is a bachelor, however the South African death certificate in 1924 mentions that he had a previous spouse (name not known, but deceased about 1890, which would roughly correlate with Helena Whiteman in Aus). Also the 1906 marriage cert is to a Hellena Brown (not Helena born Ryan as stated on death certs & probates..... however, it states she is a divorcee, so maybe she was born Ryan, married Brown and then married Wall. On her probate, her property was valued by R. Brown - so maybe there is a Ryan-Brown connection.
From the original Wall family in Greenwich, John James's brothers and uncles spread all over the world, so there would have been family connections in Aus as well as South Africa, which could explain a move to South Africa after the death of his wife/child.
Even though James John was born in Greenwich, the family had moved to Essex by the 1880's. His father Charles Robert Wall died in West Ham, Essex in 1885 and his mother (Emma Spry Stephens) was in Essex in the 1891, 1901 and 1911 censuses.
His brothers:
Robert Frederick - moved to Worcestershire
William Denham - moved to Essex
Frank Henry Patrick - moved to Tonga, then NZ
Dudley Charles - moved to USA (but possibly Canada before that) ... and newspaper obituaries mention travels to Australia
and uncles:
William Wall - to New Zealand
Frank Wall - to New Zealand
James Edward Wall - to South Africa
still circumstantial evidence, but looking likely that these are the same James John Wall's.