If he is pressing & cleaning and replacing missing pieces with an undetectable married wrap, all of those Hulk 181s may actually have been upgraded and given a blue label had they gone through CGC's grading process (as opposed to the dishonest short cut reholder).
The bolded part above is what I'm not sure is achievable. But, if we don't have one of those to examine, we can't be sure there is a missing coupon/piece/MVS.
Looking forward to the detailing of the Mark Jeweller switcheroos, which I think is agreed is a similar scam with a different twist (and the one that kicked this whole thing off).
If I'm not mistaken, examples comicwiz has posted thus far involve same book/same cert #/different grade/different label color.