I was at Vung Tau in Vietnam in July of 69, and happened to be behind a green 2 1/2 ton truck full of guys wearing short pants with hats whose brims were turned up at the side. They had had a few containers of malted anesthetic, it seems, and were spoiling for a fight! Some US GI's accomodated them, and lots of brawling, fun and then back slapping ensued. The GI's were then hauled up into the truck for the ride back to base camp where the Malt of Mass Destruction was reported to be hidden. The truck had a yellow Kangaroo on the door.
Any chance we are talking of the same lot?