Frank G.,
Thanks for the fabric lead. I have interest in the tunnels\mountains because I have a few to make for a small layout.
I am going to try red rosin paper with Elmer's. I have ordered a gallon of theatrical white glue that dries clear with a paintable surface. Closer to the industrial white glue. and has more flexibility. Then I will use one of those on the thin wool.
I can't get into the fish glue, so I am trying to get the look with modern material.
I also think I can get the same look with acrylic paint. We shall see.