I don't know if it will offer anything new to you, or not. I thought it might. Perhaps having a name would better enable tracking someone down who had a relationship with him and could forward your questions confidentially.
One route to that might be some decent media researchers--there MIGHT be a few--who have dug into it a lot. Perhaps you could contact them as intermediaries.
good ideas...thanx...almost a thousand comments and haven’t found it yet. I’ll keep plugging.