Sorry I don’t have time right now. Perhaps I misremembered, but thought he said he would often sleep off illness in the car when the driver would take him to and from gigs when he was a teen. I trust you looked.
I would note the irony that you bemoan people for not believing something when the evidence you cite isn't there - it suggests more caution is required! From my own reading, that sums up the topic: people are open to viral theories but the proof just isn't there yet so believing it is premature. Parkinson's remains poorly understood in both mechanism and cause. It is said to be "a combination of genetic and environmental factors which might include pesticides and head injury". I imagine post-viral consequences could fit within head-injury type risk factors but we are not at a position to make statements of fact about such things.
https://pubmed.ncbi.nlm.nih.gov/22753266/
https://jamanetwork.com/journals/jamaneurology/fullarticle/2...