My submission did not go as well as I would have hoped

I recently (well, back in the beginning of April) submitted 7 Morgans. I have not gotten the final notification from NGC that they have shipped, but I did receive an e-mail last night containing the images that I paid for. Unfortunately, I only got images for 3 coins, which implies quite strongly that NGC rejected the other 4. Even the ones that I did get images for did not grade as high as I would have hoped. The highest grade that I got was an MS63 on a 1902-0, which I had thought was MS64 at least.

I will be very interested in finding out why the other 4 were rejected, and take this whole experience as an opportunity to learn a few things about what to look out for in the future.

I also have another submission, with 11 Morgans, in right now, and I'm hoping that I don't have to learn too much more... :-)