The more you do on this window, the more beautiful it gets! It's fantastic! I hope you can find something that works for the leading. There are a few products out on the market that would work but as you mentioned before, they may be too expensive for your purpose. I have use the binding on a roll that you can iron on and then sew down but that was only for a small wall hanging. It really will be a stupendous quilt when you are through. Very nice work!!!