All of your answers can be found here:
https://fohonline.com/articles/milestones/woodstock-50-years-after/
I'm pretty sure there were several LA2A's in the signal path. McIntosh power.
It's funny. I think they had something like 12 or 15,000 watts total for FOH. I have friends who were there and were far away and said you could hear the music OK. It definitely sounded like it was in the distance a bit, but it could be heard.
Now contrast that with today. Dave Rat from Rat Sound has a special subwoofer cabinet that he designed just for Coachella. EACH cabinet is 16,000 watts.
Some years ago I worked for a company that would send us to trade shows, and I was at AES in NY City at the Javitz center. I managed to get a ticket to a party that was being thrown for Eddie Kramer. It was in an art studio. So Eddie is also an amateur photographer, and he always took pics from the sessions he did. They ended up blowing up 30 or 40 of his shots to poster size, and there were pics from Hendrix, Led Zep, and KISS sessions all over the walls. We talked about Woodstock a bit, but he was more excited to talk about baseball. Turns out he's a big Yankees fan.