Hi Anne,
I sure have ... been researching this for 20 years. IGI, Scotalnd's People, other genealogists. We have only found possible matches never any physical proof that the John's or Archibald's found were one of the SA brothers.
The difficulty is that SA historians simply recorded 3 brothers and one son with no mention of age, where they came from in Scotland or their parentage. We believe John Jnr was born between 1795 (based on details recorded on his death certificate) and 1799 (possible IGI matches). This would make John Snr's year of birth around 1770, but could be anything from 1750 to 1780. Hence we can also assume that John's brother's Archibald and William were born around that time as well.
We also assume that they came from Glasgow ... because the original name for the pont built by John Jnr's son, James, across the Orange River in the late 1800's was "Glasgow Pont" ... eventually renamed to Norvalspont. The pont and nearby rail bridge across the river was a strategic point during the Anglo Boer War.
John Snr - "Their was no demand for their particular trade of comb-making and a despondent John Norval made arrangements to return to Scotland but missed his boat while visiting in Wynberg" We believe he may have taken another ship at a later date. There are no death records for John in South Africa.
Archibald - Opened a comb-maker's shop at 17 Wale St., Cape Town before moving to the Eastern Cape where he married in 1824 and went on to have 8 children. He became Gaoler in Somerset East. In 1832 he wrote a letter to the Governor of the Cape, Sir Lowry Cole, requesting a grant of land in Somerset East. In this letter he mentions that his trade was a "mason". He also mentions serving in the 74th Highlanders under Wellington at Toulouse. It is recorded that the 74th were stationed at Toulouse in 1814. If we guess that Archibald may have been about 20-30 years of age while at Toulouse, that would put his date of birth at around 1780-90. There are no death records for Archibald.
William - Not much is known about William and we suspect that he may have returned to Scotland or gone on to Australia. There are no death records for William.
John Jnr - John moved to Graaff Reinet and started a hat factory. After marrying in 1831, he moved to Colesberg in 1834 and continued the manufacture of his popular broad-brimmed hats for which Colesberg became famous. In 1837 he was appointed "pound-master and veldkornet". Owned the farm, Fosseyfontein, in the Orange Free State. In 1861 he was one of the shareholders in Colesberg's first bank which in 1863 amalgamated with the Standard Bank. His son James built and ran the pont in the town now known as Norvalspont.
Regards
Mike