G'Day Keith, you're correct mate, his name was Julian Grant and he did it for a bet of a whopping 20,000 bucks (a CB750 cost around $2,000) and he circumnavigated Oz in 19 days.
An incredible effort for the time (around 1975, from memory) as a lot of the roads he travelled were dirt, with extreme weather conditions and all sorts of nasty bitey beasts along the way. At one stage he "flipped" his 750 and destroyed his rear wheel and alternator cover, but was able to buy some parts off a local blokes bike (probably for a lot of money..........) to get his bike going again. Honda used to run a 2 page ad in most bike mags here with a pic of Julian sitting on a shiny new K6, but I'm guessing that it wasn't his bike, it looks way too pristine...........
I haven't seen the documentary, but if you find it, can you send me a copy mate? Cheers, Terry.