double warm and natural might work, but the key to those old quilts being heavy was the fabric...most of the time they pieced scraps onto old flour/sugar sacks and the backing was the same, bleached out flour/sugar sacks that were made of grid iron muslin! That fabric made for a heavy quilt!
and some times if up North they used old wool blankets for batting, and sometimes even another old quilt!
I have seen it all....
the only heavier quilt is denim/flannel or polyester from the 60's! yikes is it heavy..hehehe