OK, it's the 1960s, give or take a decade or so, and let's say you're going to stretch a car and make a limousine. Many, if not most of us, would probably choose a premium brand such as Cadillac, Chrysler, or Lincoln. But the fine folks over at Armbruster Stageway and other places seemed to have liked more "base model" cars, such as Chevys, Fords, and the now dearly departed Pontiacs.
And from 1962 to 1977 (except for 1975), Checker even built their own in-house 9- and 12-passenger "Aerobus" models. Heck, one of them, the Convoy, was designed to haul prisoners. Now that's pedestrian travel!
Here is a Checker Aerobus airport limousine. This one has "only" 6 doors, but other Checker limos had the full 8-door treatment as well.
What makes up an airport limousine? Well, they seem to be a large, lower trim level 4-door sedan, station wagon, or truck that has been stretched and has one, two, or three doors added on each side. There is usually a large roof rack for extra/oversized luggage and/or Aunt Edna. These vehicles were built for function more than form or luxury; getting passengers and luggage to and from airports and hotels quickly was their reason for being. Going to the opera or prom... not so much so.