I made them a couple of years ago by editing some images from Unwise and Jurri's flag mods and my own stuff. Intended to upload them with a nation gui/background set, but I was never happy with the gui. I have been using it so long that I do not even think about it anymore.
If there is some interest, I guess I could go ahead and upload the flags mod.
Here is a sampler that I threw together:
1rst row (left to right):
Marignon, Caelum, Atlantis, Ermor, Arcos, Ctis, Man
2nd row:
Jotun, Machaka, Pangaea, Pythium, Mictlan, Ulm, Vanheim
3rd row:
Rlyeh, Abysia, Tienchi