Be warned before watching this, the footage is completely silent. Still it is worth checking out for the shots of the convention floor at an early Trek event and especially for the parts featuring William Shatner. He is led rockstar-like to the stage and the silence forces you to really focus on his expression and the people around him.
I know I am reading into this, but I would say that he looks unhappy while he is almost being pushed through the crowds. At one point he gets bumped and it looks like he might snap, but once he gets to the stage he turns on that Shatner charm and ou don’t need to have sound to realize that he is owning the room.
I know this footage is labeled 1972, but I have not been able to confirm that as the exact year of the footage. I would have guessed it to be a little later since I had read about the 1972 Con in NYC and I don’t think Shatner was there (but I could be wrong).