Familysearch.org (FS) has the following information available – because of age of this query you may already be aware of this information
John Thelwell Owen Thomas FS ID L67Y-GF5 born 22 March 1905 born Dewetsdorp, Dewetsdorp, Free State, South Africa – died 6 September 1954 Cathcart, Eastern Cape, South Africa
John’s Father Alfred Thomas FS ID KC1L-H7B born 8 March 1871 Queenstown, South Africa – died 21 August 1960 Queenstown, South Africa
John’s Grandfather Jeramiah George Thomas FS ID KZ4T-F7W born 12 June 1829 Caernarvon, Wales, United Kingdom – died 4 March 1913 England
John’s Great Grandfather FS ID William Thomas LL7Z-HCR no helpful information
There are others listed on this tree
I suggest you go to Familysearch.org to check the information that is available
NOTE; I am passing this on for your information – I can only be guided by what is on that site, correct or not
Cheers Ross Geissmann