Alright Turtle-san
I just did a little research and found an answer that fits most of your clues and is something I know that you know about.
It indeed is a toy that has been used in battle.
It can be made of hemp
it is ancient and recognized
it can be very small or very large
it is 4 different letters
KITE !!!
If this isn't right I/we at least deserve another clue you scoundral!
