This looks like Blizzard, not Gunther's Prize. Here's what Gunther's Prize looks like.

It is/was Gunther's Prize in a friends garden. Problem is that the large original plant looked like your picture for several years but has mutated and lost most of the green streaking. This division still shows some of the green streaking. I may delete the picture.....Doesn't look like the pictures of Blizzard on the Hosta Library.

Paul, how about leaving the photo with a note explaining why it looks different. I think things like that can be helpful, not all plants look the way they are expected to for different reasons!