WOW - this is awesome! Came across these Flickr sets of pics from old mid-70's Trek cons. This sure takes me back. I was at a couple cons way back then - one in the Detroit area and one up in Toronto. The hunt continues for a pic of me as a nerd kid in the background of one of these pics! :)
https://www.flickr.com/photos/36921023@N00/sets/ (https://www.flickr.com/photos/36921023@N00/sets/)
Here's also a link to programs & flyers from many of these early cons.
http://fanlore.org/wiki/Star_Trek_Convention_Program_Books_and_Flyers (http://fanlore.org/wiki/Star_Trek_Convention_Program_Books_and_Flyers)
What a photo!