For the record, a wife of a friend of a friend translated the manual and the official advice is ISO100 for Sunny, ISO400 for a bit cloudy and ISO800 for dull. This ties up with my experience on Sunday when it actually turned out sunny and the ISO400 film I used was a bit overexposed.
Here's a couple of quick neg scans, I'll see if they print OK at the weekend.
The animated GIF is to show how one of the pictures chopped into 16 and stuck together as a flip book would look