I did find this nice sheeting in my stash. It's from the back of an old Barkcloth bedspread that belonged to my in-laws. It was in sorry shape, and there are a lot of mildew stains that I'm having to cut around, but I'm hoping that there is enough for the alternating solid squares on the quilt. It's a pretty soft minty green.
I was also happily able to salvage some of the Barkcloth. Maybe enough for a pillow or two. Pretty, isn't it?