Nice build! One of my fav 251 versions and a kit I finger from time to time!
I'll echo Russ on those ammo belts. And as they don't really show, no issue!
I like the idea of using zeltbahn - I have recently picked up on using these in some projects, so maybe it's "like minds"!
BUT... couple of things... IF you are going to have it spread out, as you do, you could make it much more realistic by attending to two things: zeltbahn had large grommets at the corners - these would be visible here and are easy to add on for that extra pop. Zeltbahn also had a head - flap for use as a poncho. Again, pretty easy to add on and make it more real.
IF you add on those grommets, you'll be able to make things pop even more by tying your ZB down with some thread! At present, it looks simply "plopped on" without tie-down - yet strange to say rather carefully positioned!
Just a thought
Bob