Beetles made prior to October 1952 had 16" wheels, but VW changed to 15" when the gearbox was redesigned for syncromesh on 2-3-4 and the ratios were changed. However VWs were not even sold in Australia until 1954, so you have zero chance of finding any of those ancient 16" wheels here.
Why would you want to do this? A 205 45 17 tyre would have a diameter of 616 mm, a circumference of 1936 mm and would turn 532 times per kilometre. Compare with a stock 165 75 15 tyre - 628 mm diameter, 1974 mm circumference and 522 rotations per km. You are actually reducing the car's gearing, raising the rpm slightly at all speeds. See
http://www.1010tires.com/tiresizecalculator.asp
I'm not sure how those tyres would go on a swing-axle rear end, either.