The thick fabric looks like it could be flour sacks, they were the same size as feed sacks only thicker and denser, about the same as unbleached muslin. Some called them milk sacks also. I reconize a lot of the top as feed sacks early 40's to early 60's and some of it is old dress fabric. One of my Grandmothers' quilts I have has several of your same fabs in it. Beautiful quilt top.