Kelly definitely did make a tasmanian pattern axe for export to australia - they were stamped dandenong.
However, I'm pretty sure that neither kelly nor plumb made tasmanian pattern axes for sale in the US. The closest pattern that we have is called the Connecticut pattern - however 3lbs seems to be the most common weight of a connie, though I've seen 3 1/2 and 4lb connecticut axes - whereas the tasmanian pattern seems to be exclusively 2kg or 4.4lbs.
i think most manufacturers that make an axe for export put made in USA on it - back in the day, whereas the ones sold here were not stamped made in the USA because back then it was just understood that tools or really most things you bought would have been made in the USA unless they were stamped otherwise. Similarly Walters is a canadian axe company and the axes they sold in canada were not stamped made in canada - while those meant for sale in the US were stamped made in canada.