[ERISS]

For the actual first roundels, it seems that each pilot did according their tastes. The navy one I show you was not the actual first one, as this time the first one was not considered beautiful.
I think at this time many did not know what was a Croix de Lorraine (it comes from centuries ago), it is mainly known nowadays because of the Free French. And, even, this Croix is a WW2 political thing, the first symbol of Free French was not this and is usually unknown now.
So, if you want something historical, may it like past pilotes (like the squad fighting in the Red army): draw it beautiful according to your taste lol.
That's what I'll do, if I'm not pleased with yours, if only I know how to mod the game.