Quite by accident, I found another fusible interfacing option for recycled neckties for patchwork.  This is a 100% woven cotton from Staple Sewing Aids.  The one I was sent as a substitute for my favorite (out of stock) was 122 100% Cotton.  It is available from sources online, is 45" wide and reasonable priced, and makes silk (or polyester) neckties act like cotton quilting fabric.