I'm sorry to say but this just shows how clueless you seem to be.Perhaps a quote from someone who might know what was going on in 1964 is appropriate - Jean Guichet.
"All the cars (64 model GTOs) at Spa were factory cars lent to the distributors. The drivers, too - Parkes, myself, Bandini and Bianchi - we were team drivers and would take all the prize money and split it after the race."
"Ferrari did not wish to appear to compete against customers or to break strikes in Italy, so we had to look like a private team. Ferrari provided the car and the mechanics, but the driver had to make the entry to appear that the car was not entered by the factory."
The Spa 500 was a specific GT event, unlike e.g. the 1964 Le Mans 24 hours. Prototypes were not allowed.
It made some sense for Ferrari - who couldn't enter their prototypes to this specific race - to allow their works drivers to enter this race for affiliate teams like Maranello Concessionaires, Filipinetti etc. (just to be clear: none of them were individual private entries like your text seems to suggest). I can't imagine that there was much secrecy about that.
You can't prove by the specific 1964 Spa 500 GT championship entry that, say, the GTO entries at every event in 1964 or 1965 were works team based. Sometimes they were, far more often they were not, especially when they had to win the prototype battle in the first place.