1866 Shield Nickel - RPD ; Die Cracks ; Possible DDR

Well, I think I found something. After my standard full obv and rev images, my images show:
1) RPD
2) Obv die crack 8k to 6k
3) Obv die crack(s) around 4k
4) Rev die crack 4k
5) Rev die crack 7k
6) Rev die crack 10K AND (help me here...) I think its MD as opposed to DDR from what I've read, as it would appear the letters are thinner than they should be
7) and 8) More MD versus DDR pics

Thanks a ton to kbbpll I had a link to the 'complete guide to Shield nickels', but I still cant tell whether the RPD is 01.4 01.5 or 01.20 - and none of those list die cracks.

What's my next step?

PS: if you see the file names, go easy on me. I spelled shield wrong on the first pic and did a copy/paste to every image name, only altering the end of the name.