Perfect post for Halloween, thanks i like a graveyard visit.
You're so right about those windows. They would make great patchwork OR even a great quilting pattern... I really love that idea!
Seeing those windows with the wonderful patterning reminded me that there's an iron-on black tape (maybe in other colours too) that is sometimes used as 'leading' for stained glass quilts. It would be perfect for re-creating those windows on fabric. Think it's made by Clover.