For air at least there are some options left to be added. W/o copy pasting the Mustang all over.
The D-38 series and its variants would be good addition for lower tier props.
As for jets, the Vampire and the Venom could still be added.
The Mirage has also some more variants left, such as an early model or the recon version.
The Aiguillon (N-20) would certainly be am interesting jet aircraft, unique, although only produced as a prototype.
Another unique aircraft would be the F-5E/F, a F-5E with the wings of an F-5F.
And finally, the Milan, as it was a Swiss-French prototype.