Excellent work Lucas. I'm really sorry to hear about the decal problem. I've had a look through all my spare decals, even at some small vehicle stars, but can't find anything small enough. If the broken decal is still in place, all I can suggest is this;
First, brush on some clear gloss varnish, and let it dry thoroughly. Then, using the cirlce and star as the outline, try to touch in the star first, with white paint. When dry, spot some red on the circle, then touch in the blue of the background disc. The outside of the blue disc can then be touched in with the camouflage colour, to straighten any mialigned area. When it is all dry, apply the required clear coat after first giving the area a coat of gloss clear, to provide an even surface.
It might not be perfect, but will possibly help. Meanwhile, if I find any suitable stars, I'll let you know, so that you can correct the problem later.