People Express....I remember flying them from PWM to EWR in 1984. What did they call that terminal—it wasn't Terminal C then. Wiki says it was the North Terminal. That rings a bell.
I remember the last minute flight was cheap....like $25 in mid August. That was my first flight with them when I was 14. I went to a camp in Maine which usually hired buses (Trailways type) to take the campers home to the New York area at the end of the season. There was also a Boston bus. Well that year, they combined the Westchester and NYC buses into just one bus but there were maybe 5 more campers than room on the bus so they asked for volunteers to fly home. I remember raising my hand ASAP.