That is a beautiful top. I have also been thinking about making a duvet cover. I have a feather comforter, and the cover that I bought for it many years ago is very plain (maybe ugly) and starting to show some wear. I hadn't thought about piecing a cover, but that would combine the best of two worlds - a lightweight feather comforter with a pretty pieced top. I would probably quilt it fairly extensively, to protect the seams and to make the top even more beautiful.