I have been reading 'Born on the Hill End Goldfields' by A.E. (Bert) Howard, published in 1987. The book appears to have been self-published. In it, the author (born in Hill End in 1896 - 31198/1896 HOWARD, ALBERT E, f: ALBERT P, m: NANCY J, HILL END) reminisces on his time in Hill End from 1896 till he departed the area around 1918. While learning a great deal about the district, I was excited to read a short section mentioning my g-g-g-grandfather Thomas TREVITHICK on page 65 (Chapter 15):
"As I was not learning much and not interested in school my father got permission from Mr Harvey for me to be absent from school for periods of up to three weeks, during which time I got a job feeding the battery at my father's mine. My mate at the battery was Tom Trevidick, a grand old man over seventy years of age, I think he was nearer seventy five. It was pretty hard work for me but with his help we used to do a good day's work with enough energy left to climb the mountain at night. We were known to everybody about the district as 'the old man and the boy'."
Note the hard 'th' in Trevithick being written as 'Trevidich'. This is also evident on the headstone of Thomas' third wife Mary Ann Trevithick nee GREEN buried in 1949 at nearby Kandos NSW (http://thehistoryofmatt.blogspot.com/2008/12/wives-of-thomas-trevithick.html), with her surname engraved as 'Trevitich'.
This is the only first-hand piece of information I have found regarding Thomas so far. The author stated in the next paragraph that at age thirteen years and ten months he left school, so the author was working with Thomas Trevithick prior to 1909. Thomas Trevithick was aged 70-75 between 1905-1910. This means Thomas Trevithick was working at mines up to near the end of his life in 1913. The description is also consistent with the occupation 'engine driver' given in is death certificate. It would be interesting to determine the mine he was working at. Hopefully the book will reveal the particular mine his father, and therefore he and Thomas, were working at.