N943 is taken. It's currently assigned to a North American TB-25N registered in Borrego Springs, CA.
See the full aircraft record →A tail number only frees up if the owner deregisters the aircraft or moves it to a different N-number — and even then the FAA holds it before releasing it to the public.
N943 has been worn before. Past registrations from FAA deregistration records:
Tails one nudge away from N943 that aren't assigned or reserved: