Whatever the seller centsless produces is also accepted by
ebay. I believe he calls his basement the home of NNC.
ebay was much better at catching the numerical grade assignments, as well as reading and responding to reports of counterfeits and fakes, when they still had a small staff dedicated to that pursuit.
They no longer do, as has been mentioned on this forum several times.
If you report it, it usually results in it being removed. I've seen a number of those pulled after just a few hours of being reported, so someone at
ebay is at least reading the reports.
Technically, you aren't supposed to use ANY form of the numerical grade unless it is one of the four accepted
TPG's, but there simply isn't anyone watching for violations.