>the weight of evidence favours the idea that driving on the left was the historical norm, with the alternative a result of a conscious desire to break with tradition.<

Thanks Max - please let me know if you find it!

As for islands, I consider Australia an island and Australasia a continent. I was using 'island' as shorthand for 'island with a single unified governmental structure' - although if I analysed this I might find that my own native land (Britain or England depending on whether I'm thinking about life or rugby - I leave it to you to work out which is more important!) doesn't quite fit the definition....

I long ago gave up trying to remember how many continents there were when I realised I didn't know whether Asia and Europe were two continents or Eurasia was one.