Vol."5"

So 5.1 is basically the enhanced version with cleaner line drawings while this is the pencil sketches he drew?

Base +8, observer1980 +14

I'm not sure myself if this should be considered duplicate or not. It's basically the same stuffs, but these are the original sketches and an entirely different book. I know some people who actually hunt sketches and line drawings for their collection.

Base +9, observer1980 +14

This is volume 5, not volume 5.1 as people incorrectly renamed it.

Base +30

https://www.doujinshi.org/book/401011/Getsu-Ka-Sui-Moku-Kin-Do-Nichi-5/

Base +50