Hi Jan
I am doing a family tree for a friend who is the grandson of John Christian Welman, so am working from his recollections and memories, his mother was named Jacoba Wilhelmina Welman nee Groenewald, was married to his father William Henry Welman in 1952. William Henry Welman was the child of John Christian Welman born 1932 and was aged 4 in 1936 when his father died. John Christian Welman was married to a woman named Nancy Elizabeth, born Cooks I believe, but also known as Welman, Estherhuizen and Koekemoer, who died in 1966.
The military history stems from the fact that my friend was given his grandfathers war medals (unfortunately they were stolen) so a search of John Welman throws up several possibles..............among them a John Welman who signed up in 1901 at (it says aged 18 and 6 months) giving a possible birth date of around 1883 as a private.
The record I have, and at this stage it is still just guesswork, is from the WW1 pension records 1914-20.
Info as follows, East Kent Regiment, The Buffs, John Welman, parish of St Albans, Town of Devonport, County of Devonshire...............there is a no. 6522 and o another record I found and have ordered, the number is 46522 and relates to medals of which I know nothing, but a '14 clasp and star or rose is mentioned.
My friend was also given his grandfathers bayonet, which was also stolen, if that helps.......The trail has now grown cold with both John Christian Welman and Nancy Elizabeth Cooks and records in South Africa are scanty.
There is also a connection with Kimberley in South Africa, as William Henry Welman was a chef on board the famous blue train and met his wife Jacoba in Kimberley.
And that, is as much information as I have, I cannot locate marriage or birth certificates for Nancy or John, only a death notice for John which lists Nancy as the spouse.
I have the same Welman possibles as you have suggested, but don't really know where to go next.....outbound passenger lists from the UK don't throw anything up.