It's a bit hard to tell from the pictures, but are the bits of green in the margin sunken tissue? Are they visible from both sides of the leaves? If so, there's a good chance it is HVX, but if you could get your hands on a test strip, it would be good. Are you on Facebook? If so, there is a group for Hosta Diseases with some very knowledgeable people there as well. You might consider posting them there as well.
