marks

Best method/product for removing swirl marks from plastics?

So I just re-shimmed all my exhaust valves, went very well... then came setting the timing because I was dumb and didnt ziptie the chain to the other sprockets, so the timing was off when I reinstalled the exhaust cam. I have the two cam timing marks perfectly opposing each other, the T on...

There are no scratches at all but there were some spots that I can't explain. I bought the used 2008 front calipers pairs, the caliper and other parts are in pretty good condition. However the set of pistons doesn't look clean no matter what cleaner I used to clear off those marks ...no...