Breguet 941

There isn't to many designers building for 2004.
With 2020 coming out there will be less.
Why not email the designer of the one for FSX and see if he is willing to make a few changes to it so it will work in 2004.

I contacted, but unfortunately they do not have the will and desire to make the same plane for FS 2004

I'm glad you went to the trouble of contacting them, if you didn't you'd always wonder.
Too bad they can't help.
Look into some programs and maybe you can make that your next progect.