Hamish, Was this T line you speak of any relation to Diamond T?? Being bought out by IH in 1979 they must be no relation to the T Line of Harrisburg PA which was founded by some of the old Osterman Diamond REO Giant people in the early 2000's.
t line series acco has no connection with diamond t
first of them were built for the army here by ihc oz
to fill a contract for 4x4 and 6x6 transporters
they[ ihc] them put them into civilian use as 2x4
they were originally AACO which stood for Australian A series Cab Over
next was C series hence ACCO