Hi All,
Typical, after an hour playing with no results and THEN i post in here i find the solution within minutes 
So, overview was that i was not getting any (…) 3 dots besides the postage fields in the inspector and then i came across this post : Shipping profiles not being used by garage sale and no design store
The above post told and showed me what to look for, once i set a rate as default in the preferences screen of garagesale for both the AU site AND THE USA site - voila it was working…
Thanks for reading, and the site.