Andy,
First triple road test in Oz was an orange drum brake 3C, I think AMCN did the first test and it had the original 200mm headlight.
When Two Wheels Australia tested and published in November 1973, it had a 7" replacement headlight, word was that Two Wheels Australia had an accident after they had picked up the 3C and before they took any photo's.
to answer your question, mid 73, would have been on the boat for a minimum of 2 months, back in those days the wharfies never got anything of the docks in less than a month, usually 6 weeks
jacko.