I just spent a few hours (over the past few days) trying to figure out the difference in #2 printings. I don't think that corner thingy is consistent, but I could be wrong, and I will look into it.
From what I've seen so far - out of about 50 books on the web (ebay etc) - there are TWO distinct FIRST prints. The blue is offset to the right on most, but for some the blue is offset closer to the bottom (and sort of in the middle) on others.
The second print #2 seems easier *to tell, but that's a whole other (lesser) story.
Along the way, I may have discovered how to detect a #2 counterfeit. However, I think a bit more investigation is needed, and it's pretty damn hard to tell, especially from blurry cell phone photos.
In reality, investigating this is raising more questions for me, like: "why does there seem to be two print runs for the first print", and other crazy thoughts that I won't bring up right now, and might cause mass hysteria.
I probably sound delirious trying to explain it now, so I will promise to get back to everyone here with a more concise explanation when I am in my right mind and have it sorted out.