I would have to go out and check again....but I believe my back seat pad is foam....if I remember correctly I replaced all my horse hair pads with foam except one seat back which I had to go with rubberized horse hair....the trick is when going to pnp look for a w123 that has leather interior....the pads are always foam in my experience.....but since I had untreated horse hair pads originally, like the op said.....my cloth to hold the skins to the frames rotted...

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