I just had the driver's seat out of my 260E yesterday. There are coil springs along the front & rear edges. Then there are the typical "couch" zig-zag springs, for lack of a better word, across the middle. These fold back in a sharp angle that goes down to the frame. At the fold is some pretty hard twist (torsion) as the angle changes. Three of mine had broken right in this twist. All were on the left side, so I sat with a list to port. I rolled up a piece of scrap outdoor carpet and stuffed it into where the angles should have held the seat up. I have the scratches to prove it.
I put a similar piece on the unbroken side and another roll across the front
While I was in there, I put a flat piece of carpet between the zig-zags and the horsehair padding.
Dramatic difference. Now, it feels good to sit on and I don't do the old "slide up hill" motion t when I get in the car.
My seats (all manual, no power) have a knob on the side of the back cusion, that makes them push up in the lumber area. On a positive note, I did find almost $2 in change under the seat.
