Nah, it's a pretty flawless book other than the stamp. I wouldn't waste people's time with a question on a book with obvious flaws. Why would you assume there were other flaws? I used to run a comic shop on ebay, and It isn't my first time submitting to CGC, but it's been a while. I wasn't even asking anyone to grade my book. That's easy. I do know that date stamps won't always detract from grades, but couldn't find any info on the affect of other USPS stamp markings on grading, since it isn't a production flaw, but it was a marking applied through the distribution process.