You’re right about the bottom corner being buttoned up to keep it from dragging.
on your second pic you can see the draw strings stitched into the plash in a crescent shape? By pulling these tight you will form the square into a cape shape with hood (hope that makes sense?)
you can see a pic of mine from behind in the crl picture library:
The material isn’t wool, it is more like a canvas and, to perform its intended military function, it has a waterproof coating. The technique I found for dyeing is simple persistence, keep dyeing it until it gets to colour you want, I think mine took 4 rounds. I then weathered by spraying various shades of grey acrylics.
Any questions I can help with please hit me up and I’ll help anyway I can.