Does not appear to be a convict(see research Section). Edwin appears to have been born in England. I have found one only Edwin Bourne of the correct age in the 1871 English Census and his father is Henry which fits with the grandson being called Edwin Henry Bourne. If this is correct then Edwin would have immigrated before 1891 when he married Rosetta Ann Calway.
Henry married (Sarah). ((Sarah) was born (1827).)