if you want to venture down the Blue Note original pressing labyrinth, you might consider
this book. lots of history in it too.
very very detailed, but fairly easy to understand. considering the cost of the learning curve and the astronomical prices of true original pressings it's a bargain. it lists detailed information for every single Blue Note pressing.
I bought it intending to buy a few OP's, particularly the monos. I ended up not buying any mono OP's, but the book saved me many times the cost by giving me proper info on 'seemingly original but not quite original' pressings.
I'm told this book is out of print now, so if you think you might want it at some point it might be something to pick up just in case you need it. one avoided mistake would pay for it.