I am looking for any military records which might prove that William Colston b abt 1852 in Bristol, England, served in the Royal Engineers for 6 years around 1870s and was discharged in China. He next went to NSW where he joined the Artillery and rose to the rank of Sergeant. Is it possible that some records have survived?
I have been unable to find him in the Gloucestershire births/baptisms, or the 1861 England census.
As background, he was convicted of the murder of William Davis and his wife of Narbethong, Victoria and hanged in 1891. He was a carpenter by trade. Australasian (Melbourne, Vic. : 1864 - 1946), Saturday 4 April 1891, page 25
https://trove.nla.gov.au Any help would be appreciated.