I too was there and you got it, incredible, very big sound. Because it was so small we got up close. It was loud, the power of Duane’s guitar (and the rest of the band) just knocked you over. Loved it, very memorable show.
I was there and it was incredible. Small gym, large sound. They played most of the song list from Fillmore but no encore as I recall. No Mountain Jam. Nevertheless, it was a concert to remember especially given what soon was to happen.