Not saying anything about whether this seller knows if the marbles are reworked, but we have seen people selling forgeries who had 100% (or at least high) feedback. Ebay once refused to listen to me and let people be defrauded of hundreds of dollars because the fraud was being done by someone with high feedback. They finally shut him down, but if they had looked at the evidence which we gathered here on this forum they could have shut him down earlier. Those who saw what we posted here were saved from making some bad bids.
Lots of people post links to reworked and misidentified marbles. I don't want Jeroen to catch too much flack for what other people do too.