Thanks Rory - fits exactly with the 1851, 1861 & 1871 census returns in respect of parent's names and name of the farm. Also his DoB fits with that given by the FT creator but it is unclear how they know it. The mother died in 1860 and the 1861 Census shows 4 daughters and John Jefferson is the third of six sons, the eldest four working on the farm. The father died in 1861 and by 1871 John Jefferson is Head of the household which in addition includes the 4 daughters, still all unmarried, but only one younger brother Thomas, the cousin named John Jefferson Robinson plus two servants. It all has the air of prosperity, so why give it up? In fact they all give it up and disappear off the radar for the 1881 & 1891 censuses - we know why John Jefferson disappeared and the daughters may have all changed their names by marrying. Then Thomas reappears for the 1901 census at Prospect Farm near Whitehaven in Cumbria - in the meantime he has married an Elizabeth born in Liverpool and gained two sons aged 7 & 4, his wife's niece is their governess and they have two servants - beginning to reek of prosperity. THE TWO SONS WERE BOTH BORN IN THE TRANSVAAL, SOUTH AFRICA. By 1911 they have moved to the Grange, Loweswater (i.e. Lake District) in Cumbria and Thomas is now a man of private means with 8 rooms for his family to live in and a servant to make life more pleasant. So Thomas went to South Africa as well and, unlike his brother, apparently fared well. So did the cousin called John Jefferson Robinson go as well? - he is not apparent from the 1881 census onwards.
Correction to above - with head screwed on properly this morning and remembering cousin John Jefferson was born in Wigton rather than Cockermouth he is findable on every census from 1881 to 1911 but once again there is a South African connection. In 1871 he was living with his identically named farmer cousin but working as a brewery clerk. By 1881 he had risen to be manager of the Cleator Moor Brewery, he was married to a Mary, also born in Wigton, and living in Birks Road, Cleator Moor in a house owned by the brewery and they had a servant. By 1891 he called himself a "Brewer" and had moved slightly to Lamplugh and he and Mary now had two servants but no children (they were never to have any children). In 1901 they had moved to Loweswater and had a niece living with them. All these returns have him as John J Robinson but when he fills in the form himself in 1911 he is John Jefferson Robinson and a Brewery Managing Director, he and Mary are alone again except for a servant - the servant must have been very busy as they were living in Mockerkin Hall near Cockermouth - a still standing listed building. I cannot find a record of his death but I cannot find him on the 1921 census.
So where is the South African connection in all of that - the niece, 17 year old Mary J Francks born in Cape Colony, South Africa.
Now putting my speculative/romantic hat on - did Thomas wire J J saying we are coming home, SA is not the place to be but I am very worried about young Mary who was last heard of in Mafeking. Did J J answer the call for help and found Mary but got himself besieged in Mafeking. Being a hot shot at the Cumbrian partridge and pheasant shoots he offered himself up to the MTG. As soon as Mafeking was freed he was off home with Mary in tow.