back a few years ago, I think it was Topps or OPC were clearing out a whole bunch of uncut sheets....I only recall the 1966 -69 sheets, but there were multiple copies of EACH year.....they sold off in lots (huge $$$$), and sure enuf, these perfect cards start showing up on ebay.....when each border is perfectly smooth, and centered, and the seller has 20 PSA 9's and PSA 10;s for sale....it defies common sense that these were cut back in the 60's....
this issue was re-hashed many times on the PSA boards a few years back....PSA has mistakenly graded many, but of course, since they don't make mistakes, they have never acknowledged the fact....
Further on this subject....if you see a dealer offering a whole bunch of suspicious cards, note the PSA cert number and do a search for cards that are in the same series run. Often you will see the odd card, noted as "trimmed" by PSA, and not graded....It's been a few years since I've seen these auctions in 69 OPC, so this may not be much help for other years.
note the 'perfect' borders and centering....