Coronaviruses identified in the 30's was not in humans (it was in chickens).
The Pirbright Institute patent was not an admission of finding a previously unknown virus, but was a patent to be used for the identification of antibodies against a coronavirus. Listen to the RFK jr video I posted. Around the 38 minute mark he refers to their efforts to produce a vaccine to first immunise themselves against the deadly diseases they create to depopulate humankind.