Coming to us via Moviefone and the always-on-the-hunt Stephen Hammill is this admittedly fascinating video from a 1975 Star Trek convention in Chicago. The silent film is narrated by cameraman Rich Portnoy, and it will make you long for bell-bottoms and key parties. One final thought: Never have so many flashbulbs all popped because one guy took a seat.

Watch the video after the break …