buns

Bob if your not concerned about duplicating original construction the burlap can be replaced with any non stretchable fabric. An old canvas tarp is a good chioce if you have one laying around. It will keep the
foam from being pushed thru the springs.
Use hogring fasteners to attach where it wraps
over the perimeter wire frame and don't forget to
add a few to the center springs also. This prevents the springs from spreading apart from each other
allowing excessive movement and faster wear of
the softer materials placed over the steel.