The Sargent is vinyl, right? Looks like you've put small gouges in the material, so no amount of cleaning will fix it. You could try rubbing with an SOS pad (wet) or green pot scrubber (wet), but remember you're basically "sanding" it down so all the fabric looks the same. You've gotta find a way to stop the scuffing........ perhaps standing on your footpegs to get on and off (yeah, I know it ain't man-like.....).