Couldn't you get a bushing .243 Win die, and get the proper bushing to neck it down to .224" Also get a .243 Win seater die and swap out the seater for a .224".
Keep in mind, bushing dies do not neck down brass as easily as standard dies, but it can work. You will probably have the donut at the neck shoulder junction. It will be difficult to chamber on the first firing, but in my experience it will go. After it is fired once it is perfectly fine brass.