Bench Seat question

You may not find missing or broken, only fatigued. There should be a burlap like underlayment material between spring and foam or batting. It has little steel wires woven into it. It is placed with those wires running left to right or across the springs, keeps the cushioning from going through between the springs like potato though a slicer, helps spread load across multiple springs. I mention this because we have seen it omitted from some of the so called restored seats for sale.