The surname is distinctly Ukrainian. Variant spellings of same surname: Коломиець (Russian version) or Коломієць (Ukrainian version). Today there are 25,000+ people w/this surname living in Ukraine.
Have you checked for this surname in Владивосток (Vladyvostok) & Приморский край (Prymorskij kray)?
When did he immigrate to Australia? Any idea how long he lived in Harbin?