According to the owner, the caravan was built in 1967, but we don't know how that date was arrived at.
Forum member Aza has indicated that the swan cut outs on the overhead cupboards were a feature of Westliner caravans, and one way of identifying them.
It's incredible that new manufacturers and brandnames of caravans in the vintage era keep turning up, despite the fact that we have now been researching Australian caravan history for 14+ years. Many of the new brandnames currently coming to light, like Westliner, have their origin in Western Australia. It indicates that WA continued to have its own flourishing independent caravan industry into the late 60's, and indeed later (think Baravan). However, probably because of distance, the industry in WA operated in relative isolation, and not many WA built vans appear to have found their way to the eastern states.