I considered a new windscreen for my S2 a couple of years ago as part of replacing the sealing rubber. I spoke then with the rep for Pilkington Classic, when they were still operating in the USA. As the quote indicates, I was told that Europa windscreens are all the same, regardless of model, something I had not expected. In the end, I reinstalled my original.
For the USA and Canada, I think Pilkington still has as outlet in the Seattle area.