Thanks for giving further proof. And I'm glad we are talking about it because there is a rebuttal I had for a while that I never got to write.
The evidence brought forth for the fact that CGC graded harsher back in the day and that CPR with old labels is the way to go is that "there are very little old slabs still around".
That in itself does not confirm anything. All that confirms is that people think it is a viable strategy and are willing to take the bet, like you did (there are now 4 less older slabs out there after you tried that strategy). That's all it means. It is not at all indicative of the result. And the results have been all over the place. Some have gotten better, some worse, some the same. But the big stories that people remember are the ones where it got better. And for those, all else being equal, it is just as or more likely that the reason for the grade bump was due to pressing a slabbed comic that wasn't pressed before rather than the grading standards themselves having loosened.
And, @956Ref, of the ones you tried it with, the one that puzzles me is FF 9. The market value for that book in the midgrade range doesn't offer much reward for a CPR even if you got a slight bump in the grade, so why the attempt?