It belonged to the original order as far as I know.
F-5A 22551 might have just been delivered to Libya, before the paleis revolution started. Bringing Ghadaffi to power on the trone in Libya.
And with the US advisors expelt after the revolution, F-5A 22551 might never have seen service with the Libyan Air Force, Royal or Republic. And no one cared to paint Libyan markings on the jet. It might have only flight test hours and ferry hours on the airframe