This looks impressive. As Greg said, the shins should be open.
Pepakura is a lot of work, I suggest you use epoxy resin on the surface. Put thin layers of it on the paper, one after another until you have a hard and durable material. After that you will still need to sand the surface until it's smooth and round instead of poligonal. This will take a lot of time and you might use some more layers of epoxy resin or filler.
In the end I recommend you to get the whole armor painted or if you have the skills, paint it on your own.
looking forward to this build!